Cognitive Neuropsychology Summary PDF

Cogni&ve Neuropsychology Summary Week 1: introduc&on Single dissocia&on: lesion to brain area X impairs ability to do task A but not task B o Brain area X and task A are associated, brain area X and task B are dissociated o Cannot draw the conclusion that task A and B use diﬀerent brain areas o Could be that damage on X has greater eﬀect on A than on B, or that other areas are also involved o Tasks themselves can diﬀer, be more demanding/ diﬃcult, more concentra&on or motor skills required Double dissocia&on: lesion to brain area X impairs ability to do task A but not task B, lesion to brain area Y impairs ability to do task B but not task A o Two areas have complementary processing o Iden&ﬁes whether two cogni&ve func&ons are independent of each other o Diﬀerences in performance not due to unequal sensi&vity of tasks but because of a selec%ve deﬁcit o Strongest neuropsychological evidence Our toolbox Cogni&ve psychology and behavioral research o Not directly perceive the world, rather interpret incoming informa&on o Behavioral experiments Pa&ent studies o Single vs double dissocia&on o Study brain damage o Diﬃculty with cause and eﬀect o Lesion surgery, brain s&mula&on, psychopharmacology, neurosurgery Manipula&ng the brain: TMS, pharmacology Looking inside the brain: ERP, PET, fMRI, single cell recordings Week 2: Percep&on& aUen&on Chapter 5: sensa&on and percep&on Vision Light passed through lenses is inverted and projected onto the re&na Re&na contains photoreceptors with photopigments (alter membrane poten&al of photoreceptors to trigger ac&on poten&al) Photoreceptors consist of rods and cones Rods: low levels of light, mostly at night o Distributed through the re&na Cones: intense levels of light, day&me vision o Three diﬀerent types sensi&ve to diﬀerent wavelengths of light (blue: short; green: medium; red: longer wavelengths) o For ability to see color o Cones are densely packed near the center of the re&na, the fovea Rods and cones are connected via synapses with the ganglion cells (output layer of the re&na) Axons of ganglion cells form the op&c nerve which transmits informa&on to the CNS Visual pathways Temporal re&na of the le] eye: right visual ﬁeld, doesn’t cross over, goes to le] hemisphere Nasal re&na of the le] eye: le] visual ﬁeld, crosses over, goes to right hemisphere Nasal re&na of the right eye: right visual ﬁeld, crosses over, goes to le] hemisphere Temporal re&na of the right eye: le] visual ﬁeld, doesn’t cross over, goes to right hemisphere Temporal branch con&nues ipsilateral (same side) Nasal branch goes to contralateral side, crosses over at op&c chiasm Informa&on from right visual ﬁeld is processed in the le] hemisphere Informa&on from the le] visual ﬁeld is processed in the right hemisphere Each op&c nerve projects from the re&na to the lateral geniculate nucleus (LGN) via the re&nogeniculate pathway o LGN has 6 layers o M ganglion cells send output to boUom two layers o P ganglion cells projects to top four layers Axons from the LGN project to the primary visual cortex (V1) in the occipital lobe via the geniculocor&cal pathway In short: The op&c nerve is formed from the axons of the ganglion cells. The axons that make up the medial half of each op&c nerve cross to the opposite hemisphere and form an intersec&on at the op&c chiasm. Axons in the op&c nerve synapse on the LGN and from the LGN become the op&c radia&ons that project to V1. Lesions in visual pathway - White means intact, black means damaged - Right eye blindness: op&c nerve damaged - Bitemporal blindness: op&c chiasm cut, right eye right visual ﬁeld and le] eye le] visual ﬁeld damaged (nasal re&nas of both eyes) - LVF hemianopia: lesion in V1 of right hemisphere, le] visual ﬁeld impaired o pa&ent might s&ll respond to s&muli in the blind le] visual ﬁeld àblindsight - cor&cal blindness: both V1 impaired, don’t see anything - blindsight: people blinded by brain damage can respond to emo&on expressions with pupil response, even though they are not aware of what they are seeing àamygdala receives visual informa&on independently of visual cortex Visual cortex Iden&ﬁes what and where of objects Neurons in visual system respond only when a s&mulus is presented in their recep&ve ﬁeld Visual cells form re&notopic maps that represent an en&re contralateral hemiﬁeld Cells show speciﬁcity to loca&on, orienta&on, source of input, color àfundamental building blocks for percep&on Complexity (small spots to edges to shapes) increases the deeper the visual cells are (LGN, V1, V4) àrecep&ve ﬁelds for s&muli get larger when moving deeper V4 important for color percep&on Processing in the visual cortex is not hierarchical àanaly&c process instead visual cortex many dis&nct regions deﬁned by their dis&nct re&notopic maps. visual areas: func&onal diﬀerences that reﬂect the types of computa&ons performed by cells within each area Lesions in visual cortex achromatopsia: caused by lesions in V4, inability to perceive color, and deﬁcits in shape percep&on, only see the world in black and white Akinetopsia: impairments in mo&on processing. The impairment can be very drama&c if V5 is damaged in both the le] and right hemispheres. àonly see snapshots Mo&on percep&on middle-temporal (MT) area: important for mo&on percep&on, has direc&on-selec&ve neurons that respond selec&vely for certain range of mo&on direc&on MT neurons: direc&on and speed tuning àﬁres maximally if s&mulus crosses their visual ﬁeld in a certain direc&on or with a certain speed Mo&on= interac&on between where and what lateral occipital cortex (LOC) perceives diﬀerent images and how they change, feed this info into the MT to acquire meaning LOC and MT cooperate by sharing meaning Experiment: o Mo&on task: show par&cipants a random paUern of black and white regions that were moving or not (control) o Color task: s&muli were composed of an arrangement of rectangles that were either shades of gray (control) or various colors o Take brain scans, subtract black and white condi&on scans from color scans o Color condi&on: ac&va&on medial, in V4 o Mo&on condi&on: ac&va&on more lateral, in V5 o Both s&muli produced signiﬁcant ac&va&on in the primary visual cortex compared to control Mul&modal percep&on - mul&sensory integra&on: requires that the diﬀerent s&muli are coincident in space and &me o Superior collicus: cells are mul&sensory àcombine and integrate informa&on from diﬀerent sensory challenges o Other regions: superior temporal sulcus, regions in parietal and frontal lobes, hippocampus o Mul&sensory signals more reliable as single sensory signals - Rubber hand illusion: stroke fake hand and hidden real hand, believe you feel it in the fake hand - McGurk eﬀect: lips move to other sounds (Ba ba) than heard sound (ga ga); brain makes another sound out of it (da da da) àconﬂic&ng informa&on Synesthesia Synesthesia: mixing of the senses o for example, colored hearing, colored graphemes, or colored taste, associa&ons between words and sounds, colored leUers most common Synesthesia is associated with both abnormal ac&va&on paUerns in func&onal imaging studies and abnormal paUerns of connec&vity in structural imaging studies. Synesthe&c associa&ons are consistent over &me for an individual Can be tested with a modiﬁed Stroop task Perceptual reorganiza&on Cor&cal plas&city: remodeling neuronal connec&ons Infants: cri&cal &me periods for input of vision o Cataract (grauer Starr) need to be removed within cri&cal period, removal a]erwards didn’t lead to regain of sight Blindness: at birth caused by congenital defects (cataract), perinatal insults (eye infec&ons from bacterial infec&ons), cor&cal deﬁcits from oxygen depriva&on during birth, or become blind later in life due to degenera&ve diseases o Func&onal reorganiza&on in visual cortex of congenitally blind individuals Cor&cal reorganiza&on for all kinds of sensory limita&ons àe.g. also for deaf people Cross-modal plas&city: when a sensory system is absent, inputs from diﬀerent sensory systems expands in cor&cal recruitment àmore connec&vity These neural changes are frequently associated with behavioral changes Example seeing by sound àlike echoloca&on Engineering for compensa&on Hearing aids if adequate number of hair cells s&ll func&on àampliﬁes signals Cochlear implant to bypass damaged hair cells and directly s&mulate the auditory nerve Re&nal implants: for pa&ents who become blind due to degenera&ve diseases that aﬀect photoreceptors àBypass photoreceptor cells and directly s&mulate ganglion neurons with the help of an external video camera Chapter 6: object recogni2on Object recogni&on object constancy: ability to recognize object in countless situa&ons, accommodate for viewing posi&on, illumina&on, context areas involved in object recogni&on: a hierarchy of visual processing experiment: The BOLD signal in Lateral Occipital Complex (LOC) to objects o Animals were presented in the blue regions, either formed by the mo&on of a subset of dots (mo&on object) or as sta&c white objects on a black background (luminance object). o Ac&vity was greater during these epochs compared to when the dots either moved in a coherent direc&on (direc&onal mo&on) or randomly (random mo&on). Object recogni&on is extremely ﬂexible; we can easily classify novel s&muli or recognize objects from various angles Repe&&on suppression eﬀect: less BOLD ac&va&on whne the same s&muli is seen twice Mul&ple pathways for visual percep&on Ventral stream (=what) Dorsal stream (=where) Object percep&on and recogni&on Spa&al recogni&on Not only visual system, also auditory Not only visual system, also auditory Anterior primary auditory cortex: audio-paUern Posterior primary auditory cortex: iden&ﬁes processing (what is the sound) spa&al loca&on of a sound -temporal lobe neurons: recep&ve ﬁelds always -Parietal lobe neurons (dorsal): respond encompass the fovea similarly to many diﬀerent s&muli -ac&vated if s&mulus in le] or right visual ﬁeld -Recep&ve ﬁelds exclude fovea -task: object recogni&on -Task: detec&ng presence and loca&on of a s&mulus Temporal lobe: selec&vity from simple to Parietal lobe (spa&al aUen&on) complex features Essen&al for guiding interac&ons with objects Input for motor systems: how a movement should be produced Lesions: op&c ataxia Lesions: agnosia lesions parietal lobe o agnosia: inability to process sensory informa&on àfailure of knowledge or recogni&on of objects, persons, shapes, sounds, smells o visual agnosia: deﬁcit in recognizing objects even when processes to analyze basic processes (color, shape) work § tac&le informa&on (dorsal stream input) enables to recognize object àsome informa&on of the object is processed o auditory agnosia: inability to recognize music agnosia vs memory loss: agnosia pa&ent has a deﬁcit in visual system but with tac&le informa&on (dorsal stream) he can recognize the object; person with memory loss also cannot recognize it with tac&le informa&on single dissocia&ons: selec&ve impairments using vision to recognize objects while remaining proﬁcient in using vision to perform ac&on lesions parietal cortex o op&c ataxia: can recognize objects, cannot use visual informa&on to guide ac&on dorsal and ventral stream doesn’t exist isolated, they communicate with each other seeing shape and perceiving objects - lateral occipital cortex (LOC) cri&cal for shape and object recogni&on - People perceive an object as a uniﬁed whole, not as an assemblage of bundles of features such as color, shape, and texture - Hierarchical coding hypothesis: all features processed, then more reﬁned representa&on un&l whole object o At the lowest level of the hierarchy are edge detectors. These feature units combine to form corner detectors, which in turn combine to form cells that respond to even more complex s&muli, such as surfaces o (a) The hypothesized computa&onal stages for hierarchical coding. o (b) A neural implementa&on of the computa&onal stages illustrated in part (a). o Disadvantages § Final percept by a single cell (suscep&ble to errors, or sudden loss) § Does not explain that we can perceive new objects § What if the proper&es of the objects change? (we can s&ll recognize the object) - grandmother cells: recogni&on arises from the ac&va&on of neurons that are ﬁnely tuned to speciﬁc s&muli - Ensemble theories: recogni&on is the result of the collec&ve ac&va&on of many neurons o Objects are deﬁned by the simultaneous ac&va&on of a set of deﬁning proper&es. o “Granny” is recognized here by the co-occurrence of her glasses, face shape, hair color, and so on. o Advantages § Recogni&on not due to just one unit, but to collec&ve ac&va&on of many units; losing some units just degrades recogni&on. § Novel objects are recognized due to ac&va&on of units that represent familiar features. § Agrees with single cell recordings; cells in IT prefer certain s&muli over others but are also ac&vated by other, visually similar, s&muli - top-down processing: frontal cortex can inﬂuence processing along ventral pathway o generates predic&ons about what the scene is based on context and early scene analysis àfaster object recogni&on by limi&ng the ﬁeld of possibili&es - mind-reading o decoding: brain ac&vity provides coded message (BOLD response), ﬁgure out what is being represented o can use as communica&on tool with people who are unable to communicate but s&ll have cogni&on àe.g. want to say yes think about tennis, want to say no think about walking around the house speciﬁcity of object recogni&on in higher visual areas Fusiform face area (FFA): face sensi&ve region specialized for processing certain informa&on from faces parahippocampal place area (PPA): strongly category-speciﬁc region for judgements about spa&al proper&es or rela&ons (houses, landmarks etc) Failures in object recogni&on Visual agnosia three subtypes: appercep&ve, integra&ve, associa&ve Appercep&ve visual agnosia: problem in developing a coherent concept of recogni&on o Basic components are there, can’t be assembled o Example: in Legoland seeing instead of buildings and cars only piles of Lego bricks o Object recogni&on problems become evident when a pa&ent is asked to iden&fy objects based on limited s&mulus informa&on (e.g. a line drawing, unusual perspec&ve etc.) o In the shadows test, subjects must iden&fy the object(s) when seen under normal or shadowed illumina&on. In both tests, pa&ents with right-hemisphere lesions, especially in the posterior area, performed much worse than did control subjects (not shown) or pa&ents with le]-hemisphere lesions. Integra&ve visual agnosia: perceive parts of an object but can’t integrate them into a coherent whole o Example: in Legoland, they see doors and windows but not a house o Experiment: copy a circle and two squares: copies the ﬁgure without a concept, only with drawing lines one by one Associa&ve visual agnosia: percep&on without recogni&on o Can perceive objects with visual system but cannot understand or assign meaning to them o Can see global structure, can match, can copy but s&ll cannot recognize objects, even in their own copy o Example: in Legoland, perceive a house and draw a picture of that house but cannot tell that this is a house o Brain is unable to access knowledge from visual modality o Disconnec&on of areas associated with stored object knowledge (e.g. memory) o Matching by func&on task: Subjects are asked to choose the two objects that are most similar in terms of func&on. Agnos&c pa&ents with le]-hemisphere lesions demonstrate impairment on this task. o Category speciﬁcity: e.g. only not recognize living objects (like animals), show no deﬁcits in non-living objects o When a picture of scissors is presented, the visual code may not be suﬃcient for recogni&on. § When the picture is supplemented with priming of kinesthe&c codes, however, the person is able to name the object. o (b) Kinesthe&c codes are unlikely to exist for most living things. Agnosia pa&ents: diﬃcul&es recognizing living things but not nonliving things o Nonliving things evoke representa&ons not elicited by living things (features of the object, ac&ons with it) o Living things are harder to imagine Prosopagnosia Prosopagnosia: impairment in face recogni&on Causes: lesion in ventral pathway in the occipital regions of face percep&on regions and fusiform face area o Mostly bilateral lesion due to stroke, encephali&s or carbon monoxide poisoning o Unilateral lesion in right hemisphere Congenital prosopagnosia (CP): life&me impairment in face recogni&on that cannot be aUributed to a neurological condi&on o Could arise from impaired informa&on transmission between FFA and other face processing regions Au&sm spectrum disorder (ASD): face blindness àdo not recognize faces or facial expressions o Hypoac&vity in FFA and other face processing regions or reduced connec&vity o Fewer neuron density in fusiform gyrus Agnosia in absence of prosopagnosia o]en also have alexia o LeUer strings ac&vate le] hemisphere fusiform gyrus o Need to recognize individual leUers, can’t use holis&c processing Face percep&on accomplished by holis&c processing àrecognize sum of parts not eyes, nose etc. separately Chapter 7: a4en2on Selec&ve aUen&on Selec&ve aUen&on is the ability to focus awareness on one s&mulus, thought, or ac&on while ignoring other, irrelevant s&muli, thoughts, and ac&ons. Arousal is a global physiological and psychological brain state, whereas selec&ve aUen&on describes what we aUend and ignore within any speciﬁc level (high versus low) of arousal. Goal driven control (top-down control): steered by current behavioral goals, shaped by learned priori&es based on personal experience and evolu&onary adap&ons S&mulus-driven control: reac&on is s&mulus driven AUen&onal-control mechanisms involve speciﬁc cor&cal and subcor&cal networks that interact to selec&vely process informa&on o superior frontal cortex, posterior parietal cortex, and posterior superior temporal cortex, anterior cingulate cortex, superior colliculus, pulvinar nucleus of the thalamus o damage: deﬁcits in overt and covert aUen&on Neglect Bálint’s syndrome unilateral lesions of the parietal, posterior bilateral occipitoparietal lesions temporal, and frontal cortex right-hemisphere lesion biases aUen&on toward posterior parietal and occipital damage to both the right, resul&ng in a neglect of what is going hemispheres leads to an inability to perceive on in the le] visual mul&ple objects in space at the same &me, which is necessary for crea&ng a scene. No spa&al bias (may have normal vision ﬁelds) -Ex&nc&on: presence of the compe&ng s&mulus Simultanagnosia: diﬃculty in perceiving the in the ipsilateral hemiﬁeld prevents the pa&ent visual ﬁeld as a whole scene from detec&ng the contralesional s&mulus Ocular apraxia deﬁcit in making eye movements -Can jump from object to object (some (saccades) to scan the visual ﬁeld, resul&ng in ﬂexibility) but copy only half of it the inability to guide eye movements voluntarily -neglect also in imagery Op%c ataxia is a problem in making visually -prac&ce to shi] viewpoint guided hand movements Models of aUen&on Voluntary (endogenous) aUen&on: inten&onally, top-down, goal-driven process, meaning that our goals, expecta&ons, and rewards guide what we aUend reﬂexive (exogenous) aUen&on: boUom-up, s&mulus-driven process in which a sensory event (e.g. loud bang) captures our aUen&on overt aUen&on: turn head to orient toward a s&mulus covert aUen&on: loca&on toward which aUen&on is directed could be diﬀerent from the loca&on toward which one looks (e.g. look at book but listen to conversa&on of neighbors) cocktail party eﬀect: conversa&on in busy loca&on à selec&vely aUending to perceive the signal of interest amid the other noises or covert aUen&on The cocktail party eﬀect of Cherry (1953), illustra&ng how, in the noisy, confusing environment of a cocktail party, people are able to focus aUen&on on a single conversa&on, and to covertly shi] aUen&on to listen to a more interes&ng conversa&on than the one in which they con&nue to pretend to be engaged boUlenecks in informa&on processing: stages through which only a limited amount of informa&on can pass compe&ng theories at which stages these boUlenecks occur o early selec&on: a s&mulus can be selected for further processing or be tossed out as irrelevant before perceptual analysis of the s&mulus is complete o late selec&on: perceptual system ﬁrst processes all inputs equally, and then selec&on takes place at higher stages of informa&on processing that determine whether the s&muli gain access to awareness, are encoded in memory, or ini&ate a response o informa&on in the unaUended channel could reach higher stages of analysis, but with greatly reduced signal strength. Early vs late processing o Early: neglect all red colors, look only at blue àfeature based o Late: if meaning plays a role (cocktail party eﬀect) Late selec&on: Meaning of “unaUended” material may be processed o Subjects no&ced their name in unaUended message (cocktail party eﬀect) o Seman&c content of messages can aid selec&on Neural mechanism of aUen&on Voluntary Visuospa&al aUen&on: selec&ng a s&mulus on the basis of its spa&al loca&on àvoluntary or reﬂexive ERP: P1 wave is a sensory wave generated by neural ac&vity in the visual cortex and that, therefore, its sensi&vity to spa&al aUen&on supports early-selec&on models of aUen&on ERP: Responses to the same physical s&muli (white rectangle), are compared when they are aUended (the aUend-le] condi&on) versus when they are ignored (the aUend-right condi&on). o About 70 ms a]er the onset of the s&mulus, an increased posi&ve voltage response can be observed for the le] s&mulus when it is aUended (a) versus when it is ignored (b) spa&al aUen&on increased ac&vity in mul&ple visual areas in the cor&cal regions coding the aUended target loca&ons, but not in regions that were ignored spa&al cuing leads to a faster reac&on &me single cell recordings: Single neuron ﬁring rates in V1 and V2 with spa&al aUen&on àhigher ﬁrring rate if aUen&on is paid to that loca&on o single cells for color, loca&on biased compe&&on model o if two diﬀerent s&muli in a visual scene simultaneously fall within the recep&ve ﬁelds of a neuron, these s&muli compete and interfere with each other àreduced neural response for both o aUen&on resolves the compe&&on and favors one s&muli o visual hierarchy: size of visual ﬁeld increases, greater chance for compe&&on between diﬀerent s&muli, greater need for aUen&on àaUen&on inﬂuences V4 more than V1 reﬂexive the more salient the s&mulus, the more easily our aUen&on is captured may lead to overt or covert aUen&on reﬂexive cuing or exogenous cuing: aUen&on is controlled by low- level features of external s&muli o a task reﬂexive cue (ﬂash) appearing before the task-relevant target in the same/ similar loca&on, it facilitates processing if it occurs 50-200ms, if more than 300ms pass in between, reac&on &me is slower àinhibi&on of return o early occipital P1 wave is larger for targets that quickly follow a sensory cue at the same loca&on, versus trials in which the sensory cue and target occur at diﬀerent loca&ons o if the event is important: rapidly invoke our voluntary mechanisms to sustain aUen&on longer àoverriding the inhibi&on of return why inhibi&on of return? o The facilita&ng eﬀect of an external cue works only shortly. Suppose the eﬀect of an external cue would last for seconds... o We would be con&nually distracted by all kind of things happening around us... We would not have survived.. Visual search - ﬁnd target more quickly if it can be iden&ﬁed by one s&mulus feature (e.g. color pop-out, orienta&on pop-out) àno maUer how many other s&muli present - conjunc&on search: target with two or more features àreac&on &me increases with set size - When the target s&mulus shares features (in a conjunc&on search), more voluntary eﬀort is required to locate it - feature integra&on theory of aUen&on: spotlight of spa&al aUen&on, sequen&ally search feature aUen&on - pre-cuing aUen&on to a visual feature improves performance - pay aUen&on to color or mo&on - fast in detec&ng change - both spa&al and feature aUen&on can produce selec&ve processing of a visual s&muli, diﬀerent mechanisms used, spa&al is faster and occurs earlier in visual hierarchy than feature - experiment 1) Spa&al aUen&on: a cue ( OR ) could indicate the likely posi&on of a s&mulus that was shown a]er the cue. 2) Feature aUen&on: a cue ( OR ) could indicate the likely mo&on direc&on of a s&mulus that was shown a]er the cue - Spa&al aUen&on: high accuracy already a]er 300 ms between cue and s&mulus. - Feature aUen&on: low accuracy a]er 300 ms between cue and s&mulus, high accuracy a]er 500 ms between cue and s&mulus - Conclusion: Spa&al aUen&on is faster than Feature aUen&on object aUen&on - AUen&on can be located to diﬀerent objects - object proper&es: elementary features combined in a par&cular way yield an iden&ﬁable object/ person - when spa&al aUen&on is not involved, object representa&ons can be the level of perceptual analysis aﬀected by goal-directed aUen&onal control - In an fMRI experiment one of the images (face or house) was moving back and forth o The par&cipant was asked to aUend to the moving image o Result: When the face was moving àfMRI bold increase in the FFA, decrease in PPA o When the house was moving àfMRI bold increase in the PPA, decrease in FFA space based vs object based aUen&on - Space-based aUen&on: AUen&on is directed to loca&ons in a spa&al representa&on of the visual ﬁeld - Object-based aUen&on: AUen&on selects from perceptual groups àobjects AUen&on control networks - Model of execu&ve control systems and the way in which visual cortex processing is aﬀected by the top-down control of a network of brain areas - The dorsal (frontoparietal) aUen&on network is involved in task speciﬁc, goal directed control of aUen&on. o It mediates the top-down guided voluntary alloca&on of aUen&on to loca&ons or objects o Is bilateral - The ventral aUen&onal system is involved with s&mulus driven aUen&on, detec&on of salient targets (especially at unexpected loca&ons) and the reorienta&on of aUen&on - The ventral aUen&onal system is strongly lateralized to the RIGHT hemisphere àasymmetrical - Lesions in diﬀerent parts of the ventral system led to diﬀerent characteris&c of neglect - Subcor&cal components o Superior colliculus: Pa&ents with degenera&on of the superior colliculus may have diﬃculty shi]ing their aUen&on and are slow to respond to cued targets o Pulvinar of the thalamus: Pa&ents with lesions have diﬃculty in aUen&onal orien&ng Week 3: Language Anatomy of language and language deﬁcits Language input: auditory or visual Language produc&on: motor movement and &ming Language processing lateralized to le8 hemisphere regions surrounding Sylvian ﬁssure Some areas of the right hemisphere: right superior temporal sulcus (processing prosody), right prefrontal cortex, middle temporal gyrus, and posterior cingulate ac&vate when sentences have metaphorical meaning Brain damage and language deﬁcits Aphasia: broad term referring to the collec&ve deﬁcits in language comprehension and produc&on that accompany neurological damage, even though the ar&culatory mechanisms are intact à40% of all strokes produce some aphasia Dysarthria: speech problems caused by the loss of control over ar&culatory muscles Apraxia: deﬁcits in the motor planning of ar&cula&ons Anomia: a form of aphasia characterized by an inability to name objects Broca’s aphasia: impaired speech produc&on due to lesion in posterior le] inferior frontal gyrus (Broca’s area) o speech: telegraphic, comes in uneven bursts, very eﬀoruul Wernicke’s aphasia: impaired language comprehension due to lesion in Wernicke’s area (posterior regions of the superior temporal gyrus) and in the surrounding cortex, or in underlying white maUer connec&ng temporal lobe to other areas o diﬃculty understanding spoken or wriUen language and some&mes cannot understand language at all o speech is ﬂuent with normal prosody and grammar, but o]en nonsensical conduct aphasia: damage in arcuate fasciculus that connects Broca’s and Wernicke’s areas, can understand visual/ auditory words, able to hear their own speech errors but cannot repair them Wernicke–Lichtheim model o Third region in addi&on to Wernicke’s and Broca’s area that stored conceptual informa%on about words o language processing, from sound inputs to motor outputs, involved the interconnec&on of diﬀerent key brain regions o damage to diﬀerent segments of this network would result in the various observed and proposed forms of aphasia o does not ﬁt with most current knowledge, too simplis&c Word comprehension 1. Phonology (le] boUom side, via ears) - Systema&c organiza&on of sounds in languages to construct meaning - In any given language only a limited number of the many dis&nct sounds that can be created by the human vocal apparatus contribute to construc&ng meaning - Phonemes, vowels, consonants and syllables are diﬀerent in diﬀerent languages - New borns can recognize all phonemes; but as they grow up, they get specialized in the languages they are exposed to Sounds - = changes in amplitude over &me - Auditory: Silences within words; coar&cula&on - Visual: Spaces (blanks) between words - Segmenta&on problem: how do we know where one word ends? - Diﬀerent sounds will compete àcompe&tors of input Elements of phonology - Stress, pitch, dura&on, tone àhelps to segment, as well as knowledge about words - Silence alone is not a reliable cue, so use mul&ple cues - Prosody= the melody of language o pitch changes that convey emo&on as well as linguis&c informa&on o speaker marks where word ends by changing prosody Auditory recogni&on – Variability - Variability due to: sex of the speaker, age of speaker, other gene&c and biological factors, cultural and social background, accent, other idiosyncrasies - So we can not have representa&ons of each word for each person we have ever met - Variability Problem: abstract level of phonological representa&ons from very speciﬁc acous&cs CNS techniques: Sound recogni&on - Where/how: fMRI data - Non speech o Noise: no frequency modula&on o Tones: frequency modula&on - Speech o Words o Pseudowords o Temporally reversed speech (backwards) - Primary auditory cortex = Heschl’s gyrus - Areas more sensi&ve to tones: bilateral posterior STG - Areas more sensi&ve to words than non-words: in/ near STS, le]-lateralized Neural substrates of spoken-word processing - Sound ﬁrst processed in auditory cortex o Any sound, not specialized in linguis&c input - Acous&c sensi&vity decreases away from Heschl’s gyrus; Sensi&vity to speech sounds increases - Posterior por&ons of STS are relevant to processing of phonological informa&on; bilateral to a limited extent; mostly le] lateralized 2. Orthography (right boUom side, via eyes) Models of wriUen-word processing - Strictly boUom-up - Serial: One leUer at a &me - Learning to read requires linking arbitrary symbols onto words - Selfridges pandemonium model of leUer recogni&on àPICTURE o Image demon: receives sensory input o Feature demons: decode speciﬁc features (ver&cal, horizontal lines etc.) o Cogni&ve demons: “shout” when receive certain combina&on s of features o Decision demon: “listens” for the loudest shout in pandemonium to iden&fy input - Fragment of a connec&onist network for leUer recogni&on àPICTURE o 3 layers o BoUom-up and top-down o Parallel o Nodes in each layer can inﬂuence ac&va&on of nodes in other layers by excitatory (arrows) or inhibitory (dots) connec&ons - Word superiority eﬀect: work vs wrkt o Evidence for boUom-up and top-down processing in reading àconnec&onist model Neural substrates of visual-word processing - Ini&ally, early visual areas contralateral to hemiﬁeld ~200 ms post-s&mulus onset, le] occiptotemporal cortex ac&vity (=visual word form area) - Visual word-form area o Insensi&ve to other visual s&muli (eg, faces) o Insensi&ve to lexical or seman&c features (eg, low vs high frequency words) o Insensi&ve to leUer case (]nbv FTNBV) o Insensi&ve to visual ﬁeld (ie, le] vs right presenta&on) o Lesion here causes alexia: impairment in reading - Pure alexia: cannot read words; other aspects of language are normal o Lesions in occipitotemporal regions of le] hemisphere o le] occipitotemporal sulcus (anterior and lateral to area V4) - Lends evidence to idea that the visual word-form area (le] occipitotemporal cortex) is specialized for iden&ﬁca&on of orthographic units (= leUers) Fundamentals of language in human brain storage: brain must store representa&ons of words and their associated concepts o word in a spoken language has two proper&es: a meaning and a phonological (sound- based) form, word in a wriUen language also has an orthographic (vision-based) form mental lexicon: mental store of informa&on about words that includes seman&c informa&on (the words’ meanings), syntac&c informa&on (how the words combine to form sentences), and the details of word forms (their spellings and sound paUerns) Mental lexicon three general func&ons 1) Lexical access: output of perceptual analysis ac&vates wordform representa&ons in the mental lexicon, including their seman&c and syntac&c aUributes 2) Lexical selec%on: representa&on that best matches the input is iden&ﬁed (selected) 3) Lexical integra%on: integrated words into the full sentence, discourse, or larger context to facilitate understanding of the whole message Four organizing principles 1) Morphemes = smallest meaningful representa&on unit in language o Example defroster: 3 morphemes (de, frost, er) àall units can be added to another word to add meaning to it 2) Frequency: More frequently used words are accessed more quickly than less frequently used words o Word frequency eﬀects: more frequently used word forms are easier to recognize or produce than less frequent forms o Lexical decision task: recogni&on is faster for more frequent words 3) Neighborhood of phonemes o Neighborhoods of words that diﬀer by a single leUer or phoneme (e.g. cat, bat, hat, sat) o Phoneme: the smallest unit of sound that makes a diﬀerence to meaning o Words with overlapping phonemes cluster in the mental lexicon àincoming word ac&vates words in neighborhood o Word form that shares phonemes compete which each other àhinders processing, recogni&on is slower for words with more neighbors 4) Seman%c representa%on o Representa&ons in the mental lexicon are organized according to seman&c rela&onships between words o Seman&c priming studies with lexical decision task § Word pair of prime and target presented àtarget can be real word, nonword, or pseudoword and either related or unrelated to the prime § Reac&on &me faster and more accurate at making the lexical decision for a real word target when it is preceded by a seman&cally related prime Seman&c network representa&ons of word meanings or concepts Model by Collins and Lo]us (1975): word meanings are represented in a seman&c network in which words, depicted as conceptual nodes, are connected with each other o strength of the connec&on and the distance between the nodes are determined by the seman&c or associa&ve rela&ons between the words o this impacts: strength of connec&on and distance between nodes o assump&on: ac&va&on spreads from one conceptual node to others àcloser nodes beneﬁt more than more distant nodes o organized by seman&c features àproblem of ac&va&on: How many features have to be stored or ac&vated for a person to recognize a dog alterna&ve model: based on features of concepts, this impacts ac&va&on of the concept, which requires ac&va&on of features associated with concepts Deﬁcits in mental lexicon neural substrates of the mental lexicon o Progressive seman&c demen&a: impairments in the conceptual system, but other mental and language abili&es are spared § supports the idea that the mental lexicon contains seman&c networks of words having related meanings clustered together Living vs non-living things Warrington studied unilateral cerebral lesions for the organiza&on of conceptual knowledge in the brain àfound category speciﬁc deﬁcits (rela&onship between site of lesion and type of seman&c deﬁcit) naming living things: lateral aspects of the fusiform gyrus (on the brain’s ventral surface) and the superior temporal sulcus were ac&vated as well as le] medial occipital lobe (vision) o Problems in pa&ents with lesions in anterior temporal lobe iden&fying and naming tools: ac&va&on in the more medial aspect of the fusiform gyrus, the le] middle temporal gyrus, and the le] premotor area (hand movement) o impairment for human made things: lesion in le] frontal and parietal areas conceptual representa&ons of living things versus human-made tools rely on separable neural circuits engaged in processing of perceptual versus func&onal informa&on study by Tyler about representa&on and processing of concepts of living and nonliving things in pa&ents with brain lesions to the anterior temporal lobes and in unimpaired par&cipants o asked to name pictures of living an non-living things on a speciﬁc or domain-general level o naming at the speciﬁc level requires retrieval and integra&on of more detailed seman&c informa&on than does naming at the domain-general level o domain-general level requires ac&va&on of only a subset of features, naming at the speciﬁc level requires retrieval and integra&on of addi&onal and more precise features, including size and shape o nonliving things (e.g., a knife) can be represented by only a few features, living things (e.g., a &ger) are represented by many features àmore diﬃcult to select the feature that dis&nguishes living things from each other o results: pa&ents with lesions to the anterior temporal lobes cannot reliably name living things at the speciﬁc level (e.g., &ger or zebra), indica&ng that the retrieval and integra&on of more detailed seman&c informa&on is impaired ac&va&on of the perceptual features occurs in visual cortex within the ﬁrst 100 ms a]er a picture is presented o ac&va&on of more detailed seman%c representa%ons occurs in the posterior and anterior temporal cortex between 150 and 250 ms o star&ng around 300 ms: par&cipants are able to name the speciﬁc object that is depicted in the picture, which requires the retrieval and integra&on of detailed seman&c informa&on that is unique to the speciﬁc object CNS technique: context Syntax - Rules by which lexical items are organized to produce intended meaning - sentence representa&ons are not stored - Seman&cs isn’t enough, syntax gives thema&c roles – Actor, theme, subject, object - Syntax analysis is independent of meaning - Syntac&c parsing: assign structure to incoming words - Garden path sentences: parsing words as they come in; leads to wrong parsing Syntax viola&on - Correct and incorrect sentences presented one word at a &me - Posi&vity ~600 ms a]er viola&on àamplitude larger - If we violate seman&cs, it modulates N400; if we violate syntax, it modulates P600 - Le] anterior nega&vity = word category Syntax processing - Read sentences with varying complexi&es - Increased ac&va&on for more complex structures - Increased blood ﬂow in le] inferior prefrontal cortex when par&cipants are processing complex syntac&c structures rela&ve to simple ones Word produc&on - Same mental lexicon used, so same principles: morphemic unit, lexical frequency, lexical neighborhood, seman&c rela&onship (Related concepts are co- ac&vated and hence can compete with each other) - Macroplanning: what speaker wants to express àRepresented by goals - Microplanning: how to express it o Requires adop&ng a perspec&ve o Determines word choice and gramma&cal roles - Output: conceptual message, to be formulated at gramma&cal and phonological levels - Ac&vated concept ac&vates “lemmas” (abstract lexical forms), which carry syntac&c informa&on (e.g chase -VERB) - Morphological encoding adds morphemes chase (1 syllable) →chases (2 syllables) - Phonological encoding: integrates metrical informa&on àcha-ses - Phone&c encoding produces a gestural score used for ar&cula&ng àmotor programs - Picture naming and word genera&on o Phonological encoding ac&vates Le] inferior temporal regions and le] frontal operculum (Broca's area) o Ar&cula&on ac&vates Posterior parts of Broca's area, bilateral motor cortex, supplementary motor area and insula – Ar&cula&on - Dysarthria: problem with control of muscles when speaking - Apraxia: problem with ar&culatory planning when speaking Motor control in speech produc&on - Speakers o Create internal forward model: predic&ons about posi&on and trajectory of ar&culators and sensory consequences o Provide online control of ar&cula&on - Use sensory feedback: measures sensory consequences of ar&cula&on o Enables learning motor command o Enables upda&ng internal model in light of mismatches o Enables detec&on of perturba&ons and correc&ons o Internal feedback loops - When produce words and receive altered auditory feedback: par&cipants shi] in opposite direc&on - Increased ac&vity in bilateral superior temporal cortex, right prefrontal and motor cortex Week 4: Memory - Memory is predic&ng the future by generalizing Learning and memory Learning: process of acquiring that new informa&on, and the outcome of learning is memory àchanges in synap&c connec&ons Declara&ve long-term: seman&c (facts) and episodic (experiences) memory Nondeclara&ve: procedural memory (nonconscious, can’t be reported verbally, performing procedures) Three major processing stages Encoding: processing of incoming informa&on, creates memory traces o Acquisi&on: bombarded with tons of s&muli, only some sustained and acquired by short-term memory o Consolida&on: changes in the brain stabilize a memory over &me, resul&ng in a long- term memory àcan take days, months, or even years, and it creates a stronger representa&on over &me Storage: reten&on of memory traces àresult of acquisi&on and consolida&on Retrieval: accessing stored memory traces (e.g. for decision making) Medial temporal lobe memory system: hippocampus and various structures interconnected with it àhas connec&ons to wide regions and output pathways Parietal and temporal lobe also involved in aspects of memory o Amygdala involved in aﬀec&ve processing but not with memory in general Amnesia Amnesia: Memory deﬁcits and loss, can result from brain damage caused by surgery, disease, and physical or psychological trauma Anterograde amnesia: loss of memory for events that occur a8er a lesion or other physiological trauma àinability to learn new things Retrograde amnesia: loss of memory for events and knowledge that occurred before a lesion or other physiological trauma o Can be temporally limited (only few minutes/ hours) or for a whole life span o Temporal gradient/ Ribot’s law: forgezng greatest for most recent events Brain surgery and memory loss Pa&ent H.M. surgically removed bilateral medial temporal lobe due to epilepsy o retrograde amnesia for events 2 years prior the surgery o selec&ve memory loss for personal events (episodic memory) as far back as a decade before the surgery o normal short-term memory (sensory memory and working memory) and procedural memory (e.g. how to ride a bicycle) o anterograde amnesia: cannot form new long-term memories a]er the surgery o could s&ll learn motor skills, perceptual skills (without remembering that he learned those) ànondeclara&ve long-term memory in tact extent of the memory deﬁcit depended on how much of the medial temporal lobe had been removed àposterior and bilateral lead to most severe forms o The more posterior along the medial temporal lobe the resec&on had been made, the worse the amnesia was o only bilateral resec&on of the hippocampus resulted in severe amnesia àunilateral removal did not lead to memory loss medial temporal lobes are necessary for the forma&on of long-term memories but not for the forma&on and retrieval of short-term memories, or for the forma&on of new long-term nondeclara&ve memories that involve the learning of procedures or motor skills Demen&a Demen&a is an umbrella term for the loss of cogni&ve func&on in diﬀerent domains (including memory) beyond what is expected in normal aging àneuronal degenera&on Alzheimer’s disease: most common type of demen&a (60-70%) vascular demen&a: second most common type of demen&a (15%) caused by decreased oxygena&on of neural &ssue and cell death, resul&ng from ischemic or hemorrhagic infarcts, or rupture of small arterial vessels Mechanisms of memory Short term forms of memory 1) Sensory memory = transient reten&on of sensory informa&on in sensory structures Hearing: echoic memory Vision: iconic memory rela&vely high capacity: These forms of memory can, in principle, retain a lot of informa&on, but only for short periods of &me 2) Short-term memory Longer &me course (seconds to minutes) but more limited capacity Modal model o Informa&on ﬁrst stored in sensory register, then items selected by aUen&onal processes can move to short-term storage, if item rehearsed it can move to long-term storage o At each stage informa&on can be lost by decay (informa&on degrades and is lost over &me), interference (new informa&on dis- places old informa&on), or a combina&on o Model assumes hierarchically structure Debate about hierarchically structure o short-term memory is not the gateway to long-term memory as in the modal model o memory registers can be encoded directly into long-term memory o double dissocia&on: evidence from pa&ents with impaired short-term memory due to lesions but intact long-term memory and from pa&ents with impaired long-term memory but intact short-term memory 3) Working memory limited-capacity store for retaining informa&on over the short term (maintenance) and for performing mental opera&ons on the contents of this store (manipula&on) working memory contains informa&on that can be acted on and processed, not merely maintained by rehearsal three-part working system o execu&ve system that controls two subordinate systems: the phonological loop, which encodes informa&on phonologically (acous&cally) in working memory; and the visuospa&al sketch pad, which encodes informa&on visually in working memory o phonological loop involves a rehearsal of informa&on to keep it ac&ve for both auditory and visual inputs o visuospa&al sketch pad has bidirec&onal arrows because informa&on can be put into it, manipulated, and read out modality speciﬁc Each system can be damaged selec&vely by diﬀerent brain lesions Long-term forms of memory 1) Declara&ve memory (= explicit memory) memory for events and for facts, both personal and general, have conscious access, can verbally report episodic memory: events that the person has experienced that include what happened, where it happened, when, and with whom àcontext o self as agent or recipient of ac&on o what, where, when, who of a single episode (context) become associated and bound together and can be retrieved from memory as a single personal recollec&on seman&c memory: objec&ve knowledge that is factual in nature but does not include the context in which it was learned o fact can be learned a]er a single episode, or it may take many exposures o reﬂects knowing facts and concepts 2) Non-declara&ve memory (=implicit memory) not expressed verbally; it cannot be “declared” but is expressed through performance, unconsciously also called implicit memory includes priming, simple learned behaviors that derive from condi&oning, habitua&on, sensi&za&on, and procedural memory independent of medial temporal lobe brain structures involved: basal ganglia, the cerebellum, the amygdala, and the neocortex Procedural memory required for tasks that include learning motor skills and cogni&ve skills depends on extensive and repeated experience àform habits, learn procedures procedural learning can proceed independently of the brain systems required for episodic memory disorders of basal ganglia (e.g. Parkinson): impairments in acquisi&on and reten&on of motor skills Priming Priming refers to a change in the response to a s&mulus, or in the ability to iden&fy a s&mulus, following prior exposure to that s&mulus can be perceptual, conceptual, or seman&c Perceptual priming acts within the perceptual representa&on system (PRS) o structure and form of objects and words can be primed by prior experience; depending on the s&mulus, the eﬀects persist for a few hours to months o word-fragment comple&on task: only some leUers from a real word shown from either an ini&al list or new words àfaster in comple&ng words from list due to priming o perceptual priming can be damaged even when explicit memory is not impaired àdouble dissocia&on for declara&ve and nondeclara&ve memory systems conceptual priming: nonconscious, impaired by lesions to the lateral temporal and prefrontal regions seman&c priming: prime and target are diﬀerent words from the same seman%c category (associa&ve network) o typical eﬀect: shorter reac&on &me or increased accuracy in iden&fying the target or categorizing it àbrief, lasts only a few seconds Classical condi&oning - CS paired with US and became associated with it - delay condi&oning: the US begins while the CS is s&ll present - trace condi&oning: there is a &me gap, and thus a memory trace is necessary - damage to the hippocampus does not impair delay condi&oning but does impair trace condi&oning non-associa&ve learning - does not involve the associa&on of two s&muli to elicit a behavioral change - Simple learning as habitua&on: response to an unchanging s&mulus decreases over &me - Sensi&za&on: response increases with repeated presenta&ons of the s&mulus - involves primarily sensory and sensorimotor (reﬂex) pathways medial temporal lobe memory system forma&on of new declara&ve memories (both episodic and seman&c) depends on the medial temporal lobe medial temporal lobe includes amygdala, the hippocampus, and the surrounding para- hippocampal, entorhinal, and perirhinal cor&cal areas Evidence from amnesia - H.M.: half of the posterior region of his hippocampus was intact, 5cm of medial temporal lobe removed - pa&ent R.B.: lost his memory a]er an ischemic episode during heart bypass surgery, anterograde amnesia, lesions restricted to CA1 pyramidal cells of hippocampus - transient global amnesia (TGA): lesions in CA1 ﬁeld of hippocampus, retrograde amnesia but memories return - Alzheimer’s disease: extent of atrophy in the medial temporal lobe in AD pa&ents is most closely related to their deﬁcits in episodic memory - Lesions that damage the lateral cortex of the anterior temporal lobe but do not extend to the hippocampus can lead to severe retrograde amnesia for seman&c memory but not episodic memory Evidence from animals with medial temporal lobe lesions Mishkin research: removed surgically either the hippocampus, the amygdala, or both of monkeys o Tested with delayed nonmatch-to-sample task: a) The correct response has a food reward located under it; b) The monkey is shown the correct response, which will yield a reward for the monkey; c) The door is closed, and the reward is placed under a second response op&on, d) The monkey is then shown two op&ons and must pick the correct response (the one that does not match the original sample item) to get the reward. Here the monkey is pictured making an error. o monkey’s memory was impaired only if the lesion included both the hippocampus and the amygdala àThis ﬁnding led to the (incorrect) idea that the amygdala is a key structure in memory Zola-Morgan research: extend ﬁndings of Mishkin with more selec&ve lesions o surgically selec&ve lesions of the amygdala, the entorhinal cortex, or the surrounding neocortex of the para-hippocampal gyrus and the perirhinal cortex o results: lesions of the hippocampus and amygdala produced the most severe memory deﬁcits only when the cortex surrounding these regions was also lesioned o When lesions of the hippocampus and amygdala were made but the surrounding cortex was spared, the presence or absence of the amygdala lesion did not aﬀect the monkey’s memory àshowed that amygdala cannot be part of system that supported the acquisi&on of long-term memory o Follow-up work showed that lesions of only the para-hippocampal and perirhinal cor&ces also produced signiﬁcant memory deﬁcits CONCLUSION: hippocampus cannot func&on properly if these vital connec&ons are damaged amnesia more severe if hippocampus and surrounding structures are damaged than if only the hippocampus is damaged Electrodes implanted in rat hippocampus: place cells, ﬁred only when the rat was situated in a par&cular loca&on and facing a par&cular direc&on àloca&on-speciﬁc ﬁring o As rat moved, the ac&vity of speciﬁc CA1 and CA3 hippocampal neurons correlated with speciﬁc loca&ons o CONCLUSION: hippocampus represents spa&al context, involved in spa&al naviga&on learning, has cogni&ve maps Morris water maze: tank ﬁlled with water, visual cues above water, invisible plauorm in the water that needs to be found o Rats dropped in water in diﬀerent trials, &me to swim to plauorm became shorter with each trial àlearned where plauorm is in rela&on to visual cues o Rats with hippocampal damage: didn’t learn to associate visual cues with plauorm’s loca&on, instead they swam randomly § They can learn a repeated, prac&ced task (a s&mulus–response task) but are unable to relate space informa&on with diﬀerent contextual informa&on o CONCLUSION: hippocampus needed in retrieval of both short- and long-term memories Long-term memory storage and retrieval Feedback system between hippocampus and neocortex for memory storage and retrieval retrieval error: remember events that never happened True memories are associated with greater ac&vity in the medial temporal lobe and sensory areas false memories are associated with greater ac&vity in frontal and parietal por&ons of the retrieval network àdon’t ac&vate sensory areas, instead regions for top-down cogni&ve control Frontal cortex encoding and retrieval àlecture? le] hemisphere is more involved in processes coded by linguis&c representa&ons, whereas the right frontal cortex is more involved in object and spa&al memory informa&on parietal cortex retrieval - medial temporal lobe can produce both retrograde and anterograde amnesia Memory consolida&on Consolida&on is the process that stabilizes a memory over &me a]er it is ﬁrst acquired occur at the cellular level, as well as at the system level hippocampus: essen&al for the early consolida&on and ini&al storage of informa&on for episodic and seman&c memories standard consolida&on theory: considers the neocortex to be crucial for the storage of fully consolidated long-term memories, whereas the hippocampus plays only a temporary role o Cri&c: doesn’t explain why some people who have amnesia due to hippocampal damage have good long-term memory and others have severe loss. Mul&ple trace theory: long-term stores for seman&c informa&on rely solely on the neocortex, while episodic memory, consolidated or not, con&nues to rely on the hippocampus for retrieval Sleep supports memory consolida&on, perhaps when hippocampal neurons replay paUerns of ﬁring that were experienced during learning. Stress aﬀects episodic memory consolida&on when high levels of cor&sol inﬂuence hippocampal func&on Week 5: cogni2ve control Problems with goal-directed responding in animals - Animals are trapped by ins&nc&ve behavior related to food consump&on, going against their goal (of gezng food) Cogni&ve control - what diﬀeren&ates goal-directed behavior from automa&c, habitual behavior, and what is required to achieve it = cogni&ve control - allows us to override automa&c thought and behavior - allows informa&on processing and behavior to vary adap&vely from moment to moment depending on current goals, rather than remaining rigid and inﬂexible - Goal oriented ac&on: knowledge of a causal rela&onship between ac&on and reward (outcome)+ assessment of this reward - Habit: s&mulus driven responses, no longer ‘under control’ of an outcome - Dis&nc&on is graded àautoma&c behavior can be ‘brought under control’ History - The idea, and even evidence, that the frontal part of the brain is important for ‘thinking’ is very old. - The func&on is described in various terms: aUen&on, cogni&ve control, planning, execu&ve func&oning - AUen&on includes percep&on, language, motor control and emo&on - Homunculus: liUle person in your head doing the process, does not explain how Anatomy of cogni&ve control Cogni&ve control (execu&ve func&on: set of psychological processes that enable us to use our percep&ons, knowledge, and goals to bias the selec&on of ac&on and thoughts from a mul&tude of possibili&es) àEnables goal-oriented behavior Frontal lobe o Primary motor cortex, anterior and ventral to it secondary motor areas Prefrontal cortex (PFC) o Four regions: the lateral prefrontal cortex (LPFC), the frontal pole (FP), the orbitofrontal cortex (OFC), and the medial frontal cortex (MFC) o Matures late compared to rest of the brain o coordinates processing across wide regions of the central nervous system (CNS) o almost all cor&cal and sub- cor&cal areas inﬂuence the prefrontal cortex either through direct projec&ons or indirectly via a few synapses. Control system 1: LPFC, OFC, and FP, supports goal-oriented behavior o Includes working memory system that recruits and selects task-relevant informa&on o Involved in: planning, simula&ng consequences; and ini&a&ng, inhibi&ng, and shi]ing behavior Control system 2: MFC o essen&al role in guiding and monitoring behavior o works in tandem with the rest of the prefrontal cortex, monitoring ongoing ac&vity to modulate the degree of cogni&ve control needed to keep behavior in line with current goals cogni&ve control deﬁcits - frontal lobe lesions: Show persevera&on, are apathe&c, distrac&ble, or impulsive; unable to make decisions, plan ac&ons, understand the consequences of their ac&ons, organize and segregate the &ming of events in memory, remember the source of their memories, and follow rules; disregard social conven&ons - bilateral PFC lesions in monkeys: loss of goal-directed behavior, act only s&mulus-driven - deﬁcits of cogni&ve control also hallmark of many psychiatric condi&ons Goal oriented behavior - based on the assessment of an expected reward or value and the knowledge that there is a causal link between the ac&on and the reward - require processes that enable us to maintain our goal, focus on the informa&on that is relevant to achieving that goal, ignore or inhibit irrelevant informa&on, monitor our progress toward the goal, and shi] ﬂexibly - Habit: no longer under the control of a reward, but is s&mulus driven, automa&c Working memory Delayed response task o working memory task: need to remember the loca&on of the food from the previous task o Associa&ve memory task: the food reward is always hidden under the same visual cue, and the loca&ons of the two cues are determined randomly o working memory is required in the ﬁrst task because, at the &me the animal responds, no external cues indicate the loca&on of the food àimpaired with frontal lobe lesions o Long-term memory is required in the second task because the animal must remember which visual cue is associated with the reward àNot aﬀected from frontal lobe lesions many species must have some ability to recognize object permanence àsurvival reasons diﬀerences between species may be found in the capacity of the working memory, how long informa&on can be maintained in working memory, and the ability to maintain aUen&on within LPFC cells characterized as “what,” “where,” and “what–where” were observed o “what” cells responded to speciﬁc objects, and this response was sustained over the delay period o “Where” cells showed selec&vity to certain loca&ons o “what–where” cells, responding to speciﬁc combina&ons of “what” and “where” informa&on o cells in the LPFC exhibit task-speciﬁc selec&vity and remain ac&ve only if the monkey uses that informa&on for a future ac&on alterna&ve hypothesis: task demands o prefrontal ac&vity reﬂects speciﬁcity in representa&on of task goals àBut goal does not necessarily equal content o interac&ons with other cor&cal areas that are specialized in processing speciﬁc types of informa&on o tested with 4 s&muli, sequen&ally: faces and scrambled faces, remember faces, varied: number of scrambled faces § Measuring: fMRI-BOLD, lateral PFC and fusiform area (FFA) àBOLD response in PFC increased with load N-back task: responses are required only when a s&mulus matches one that was shown n trials earlier. o con&nuous stream of s&muli, par&cipants are instructed to push a buUon when they detect a repeated s&mulus o require both the maintenance and the manipula&on of informa&on in working memory o Ac&va&on in the LPFC increases as n-back task diﬃculty is increased o working memory demands of the n-back task require maintaining the goal, staying on task (aUen&on), and keeping track of the visual s&muli Encoding vs maintaining - Ac&vity in LPFC: maintaining task goal - Response in FFA: encoding and recogni&on phase - Working hypothesis: Working memory ‘based in’ lateral prefrontal cortex is necessary to keep our goals / task demands online Organiza&on principle of PFC anterior–posterior gradient across the PFC follows a crude hierarchy àposterior most simple tasks, more abstract in anterior Ventral-dorsal gradient: organized in terms of maintenance and manipula&on lateral–medial gradient: related to the degree to which working memory is inﬂuenced by informa&on in the environment (more lateral) or informa&on related to personal history and emo&onal states (more medial) Decision making - norma&ve decision: how people ought/ to make decisions (what they should do) - descrip&ve decision: how people actually make it - ac&on–outcome decisions: evalua&on of the expected outcomes àgoal-oriented decision - s&mulus–response decisions: ac&ons taken that are no longer under the control of reward, simply executed in the context triggers àhabits - model-based: agent has an internal representa&on of some aspect of the world and uses this model to evaluate diﬀerent ac&ons (e.g. cogni&ve map) - model-free: only an input–output mapping, similar to s&mulus–response decisions Value and decision making making choices that will maximize value, considering the likelihood of receiving the reward and costs required to obtain it primary reinforcers: direct beneﬁt for survival ﬁtness (food, water, sex) secondary reinforcers: rewards that have no intrinsic value themselves, but become rewarding through their associa&on with other forms of reinforcement (money, status) factors that contribute to the representa&on of value o Payoﬀ. What kind of reward do the op&ons oﬀer, and how large is the reward? o Probability. How likely are you to aUain the reward? o Eﬀort or cost o temporal discoun&ng( How long are you willing to wait for a reward?) o Context: external or internal, novelty o Preference Highly inconsistent in decision-making OFC (orbitofrontal) ac&va&on was closely &ed to varia&on in payoﬀ, LPFC ac&va&on was associated with the probability of reward OFC lesion: impulsive behavior as consequence of poor temporal discoun&ng; immediate outcomes are preferred, even if it’s not a ra&onal choice Value is encoded in OFC / vmPFC, which can be used to decide which goals to pursue BOLD response in ACC correlates posi&vely with the search value (explore) and nega&vely with the encounter value (exploit), regardless of which choice par&cipants made. ACC signals exert a type of control by promo&ng a par&cular behavior: exploring the environment for beUer alterna&ves compared to the current course of ac&on Learning value - Ul&mate goal: survival & procrea&on - Implementa&on: seek rewards àlearn how rewarding (i.e. valuable) things are - Primary reinforcers: subcor&cal, old neural structures Dopamine ac&vity and reward processing Dopaminergic neurons that originate in the VTA project through two pathways: The mesolimbic pathway travels to structures important to emo&onal processing, and the mesocor&cal pathway travels to the neocortex, par&cularly to the medial por&ons of the frontal lobe ac&vity of the dopaminergic neurons is much higher when that reward is unexpected compared to when it is expected dopamine neurons project to reward centers neural self-administra&on of dopamine-enhancing drugs is rewarding electric self-s&mula&on to reward centers is blocked by dopamine antagonists dopaminergic drugs (e.g. cocaine) are addic&ve classical condi&oning experiment with monkeys o a light, the condi&oned s&mulus (CS), was followed a]er a few seconds by an uncondi&oned s&mulus (US), a sip of juice o beginning of training: cells showed a large burst of ac&vity a]er the US was presented o CS-US repeatedly present: dopamine response to the juice (US) decreased over &me; cells started to ﬁre when the light (CS) was presented o First trial: didn’t expected the reward à results in a posi&ve RPE, because the obtained reward is greater than the expected reward àDA is released o Repeated pairing: animal expects the reward a]er the light à expected and obtained values become more similar, the size of the posi&ve RPE is reduced and the dopaminergic response becomes aUenuated o Increased dopaminergic response to light: experiences rewards a]er a light ﬂash, begins to associate the light with the juice àthe onset of the light results in a posi&ve RPE o If the juice is repeatedly withheld, the size of both the increase in the dopaminergic response to the light and the decrease in the dopaminergic response to the absence of the juice are reduced àex&nc&on o With repeated trials, though, the size of the RPE decreases, so subsequent changes in the value of the light will also increase more slowly. Dopamine ﬁring reﬂects reward predic&on error signals reward predic&on error (RPE): signal that represents the diﬀerence between the obtained reward and the expected reward àposi&ve (obtained reward bigger than expected) or nega&ve why predic&on errors: to learn to predict the value (of consequences of your ac&ons) damage occurs within the dopamine system: control problems will be reﬂected in behavioral changes related to mo&va&on, learning, reward valua&on, and emo&on Parkinson’s disease: deple&on of striatal dopamine o Treatment: levodopa (precursor, restore dopamine) Dopamine ﬁring in the striatum encodes reward predic&on errors, which helps you to learn how valuable something is Value-coding is an interplay of vmPFC & striatum, mediated by dopamine Goal planning Plan of ac&on - 3 components o develop subgoals o an&cipate consequences o iden&fy requirements to achieve goals - goals are hierarchical all the way down to the motor level hierarchical organiza&on of goal planning - uniquely human frontal pole for abstract reasoning àposterior- anterior hierarchy of abstrac&on - task: learn to follow increasingly abstract rules o response task, feature task, dimension task o increasingly abstract rules àincreasingly anterior representa&on - Hierarchical goal planning and deﬁni&on of appropriate sub- goals is disrupted in PFC lesion pa&ents - Control over complex ac&ons require that we: o maintain our current goal (reduce expenditure) o be able to shi] from one subgoal to another o focus on the informa&on that is relevant to achieving that goal and ignore irrelevant informa&on Dynamic ﬁltering - Prefrontal cortex as dynamic ﬁlter, not just maintenance - Goals modify the salience of informa&on àac&vely select informa&on - Problems: interference (e.g. Stroop) o PFC pa&ents have problems o PFC is important for ﬁltering (not just WM - Lateral PFC is important for ﬁltering (select/ignore) informa&on as/when it becomes important - Hypothesis: impaired selec&on process in PFC lesions leads to openness to crea&ve/ atypical solu&ons àcan perform match s&ck task beUer than normal people o an immature PFC in childhood & adolescence is perhaps an advantage when you are learning about the world! - Input or output ﬁltering, inhibi&ng or boos&ng Input ﬁltering - Test sensory input ﬁltering: UnaUended auditory clicks, evoked poten&al (EP) measured in auditory cortex of lesion pa&ents o Parietal lesion: no diﬀerence, o Temporal lobe lesion: loss of informa&on o Frontal lobe lesion: loss of inhibi&on (suppressing informa&on) of auditory cortex - Frontal lobe minimizes impact of irrelevant perceptual informa&on - Predic&on: When we externally minimize interfering informa&on, this should help frontal lesion pa&ents. o E.g in study with monkey with LPFC lesion ﬁnding the cue, turn oﬀ light during delay àreduce amount of sensory input that has to be ﬁltered out, it improves performance àinput ﬁltering, inhibi&on of informa&on - PFC lesion: pa&ents show larger response to irrelevant auditory s&muli and absence of diﬀeren&a&on for aUen&on - PFC lesion: monkeys perform ﬁne when no interfering visual s&mula&on is present during delay Output ﬁltering - Inhibi&on of ac&on: stop mid ball hit - Stop signal task: o go trial with arrow, response &me un&l buUon press o stop trial: arow appears, stop signal heard, should not press the buUon àvariable &me between onset of s&mulus and stop signal; failed if delay was too long - Right inferior frontal gyrus lesion pa&ents are slower to abort o have a longer SSRT (= stopping process) àneed longer &me to stop the movement o i.e. fail with shorter SSDs - Right IFC generates command to stop - Subthalamic nucleus implements this command – tells the whole (pre)motor cortex to stop - A]er that, a speciﬁc ac&on can be selec&vely released - Parkinson’s pa&ent treated with deep brain s&mula&on àdisinhibits cortex o motor disinhibi&on: improves movement ini&a&on o cogni&ve disinhibi&on: loss of impulse control on reward task, even behavioral addic&ons Input vs output ﬁltering - Inferior frontal gyrus: Suppression of task/goal irrelevant informa&on - Subthalamic nucleus: Global suppression of the motor cortex - Lateral prefrontal cortex: ‘Origin’ of ‘stop’ command Monitoring goal achievement Ensuring goal-oriented behavior succeeds - Monitoring system in the medial frontal cortex (ACC) o Novel responses o Required response competes with strong habitual response o Error correc&on o Diﬃcult or dangerous situa&ons - Clusters in ACC, but extends also beyond and therefore: medial frontal cortex - Func&on of ACC 1. AUen&onal hierarchy: coordinate & select diﬀerent WM buﬀers àproblem: homunculus 2. Error Detec&on: ERP signal in ACC when making an error àproblem: also ac&ve for diﬃcult tasks when you don’t make an error (e.g. Stroop) 3. Conﬂict Monitoring - Response Conﬂict - Lateral cortex represents task goals - Medial frontal cortex monitors if that goal is achieved (not just errors) - Conﬂict: allocate resources, especially when the automa&c response is (likely) incorrect Stroop task àdouble dissocia&on ACC vs DLPFC - Cue – long delay – s&mulus - Measures: task selec&on vs response conﬂict - Diﬃculty: reading (easy) vs color naming (hard) - Instruc&on: PFC as a func&on of task diﬃculty: hard (name color) > easy (name word) - S&mulus: ACC as a func&on of response conﬂict (incongruent > congruent). - conﬂict registered in ACC leads to higher ac&va&on on subsequent trial in DLPFC àadapta&on of task goal/ sezng - conﬂic&ng monitor hypothesis: Medial frontal cortex detects conﬂict and raises alarm (pay aUen&on, things are harder than we thought!) o Lateral cortex represents & adapts task goals: implements ‘control’ o Problem: ACC ac&vity seems more to reﬂect likelihood of errors than degree of conﬂict 4. Cost of Control Summary overview - Lateral prefrontal cortex o working memory o ﬁltering / inhibi&on o selec&ve aUen&on (ac&vate posterior regions) - Ventromedial /orbitofrontal cortex o value coding o coming up: emo&on, social cogni&on - Frontal pole o abstract rule learning o hierarchical ac&on goals o reasoning - Medial frontal cortex / ACC: monitoring ongoing ac&vity (modulate the degree of cogni&ve control) Week 6: Emo2ons What is an emo&on Emo&ons are embodied, uniquely recognizable, triggered by emo&onally salient s&muli without warning, have global eﬀects on cogni&on, guide behavior Under umbrella term aﬀect valence responses (posi&ve or nega&ve) to external s&muli and/or internal mental representa&ons that o involve changes across mul&ple response systems o dis&nct from moods, have iden&ﬁable triggers o can be unlearned or learned o involve mul&ple types of appraisal processes that assess signiﬁcance of s&muli to current goals o depend on diﬀerent neural systems least three components: physiological reac&on to a s&mulus, behavioral response, feeling A threatening event triggers stress which disrupts homeostasis, cor&sol release, leading to ﬁght-or-ﬂight mood is a long-las&ng diﬀuse aﬀec&ve state characterized by an enduring subjec&ve feeling without an iden&ﬁable object or trigger Neural systems in emo&on processing MacLean’s work iden&fying the limbic system as the “emo&onal” brain complex interconnected network involved in the analysis of emo&onal s&muli. o includes the thalamus, the somatosensory cortex, higher-order sensory cor&ces, the amygdala, the insula, the ventral striatum, and the medial prefrontal cortex, including the orbitofrontal cortex and anterior cingulate cortex (ACC Basic emo&ons closed set of emo&ons, each with unique characteris&cs, carved by evolu&on and reﬂected through facial expressions innate, universal, short-las&ng complex emo&ons combina&ons of basic emo&ons, some of which may be socially or culturally learned, that can be iden&ﬁed as evolved, long- las&ng feelings dimensional theories of emo&on fundamentally the same but that diﬀer along one or more dimensions, such as valence (pleasant/ unpleasant, posi&ve/ nega&ve) and arousal, approach or withdraw Theories of emo&on genera&on - James-Lange Theory: s&mulus àANS behavioral response àconscious feeling o Autonomic Speciﬁcity: Diﬀerent paUerns of ANS ac&va&on should lead to diﬀerent emo&onal experiences o Emo&on results from bodily sensa&ons, if you take away the bodily state you take away the emo&on - Cannon-Bard Theory thalamus àparallel processing of cortex (subjec&ve response) and hypothalamus (physiological & behavioral response) o Cri&cized James that physiological responses are too diﬀuse, similar ANS response for several emo&ons àautonomic speciﬁcity does not exist o Emo&onal feeling and emo&onal reac&on are independent parts - Schacter and Singer Two factor theory o Emo&ons arise from 1. Bodily arousal 2. Context- dependent interpreta&on of the arousal o arousal and behavior ﬁrst, then cogni&ve appraisal o s&mulus àautonomic arousal àappraisal àconscious feeling - Lazarus Appraisal Theory: cogni&ve appraisal (relevant, resources for it) àemo&onal response àphysiological àcoping strategy (problem- or emo&on focused) o emo&ons are a response to the risk-beneﬁt appraisal (automa&c and unconscious) o Dynamic process - LeDoux: fast and slow roads to emo&on o Two emo&on systems opera&ng in parallel o System I: neural system for our emo&onal responses that bypasses the cortex and was hardwired by evolu&on to produce fast responses that increase our chances of survival and reproduc&on o System II: includes cogni&on, is slower and more accurate, generates the conscious feeling of emo&on - Evolu&onary psychology approach to: emo&ons are an overarching program that directs the cogni&ve subprograms and their interac&ons - Panksepp’s Hierarchical- Processing Theory of Emo&on o primary-process or core emo&ons: provide our most powerful emo&onal feelings and arise straight from the ancient neural networks in the subcortex àcogni&on does not play a role here o secondary-process elabora&ons (emo&onal learning) arise from condi&oning o ter&ary-process emo&ons are elaborated by cogni&on. - Anderson and Adolphs: Emo&ons as Central Causa&ve States o emo&onal s&mulus ac&vates a central nervous system state that, in turn, simultaneously ac&vates mul&ple systems producing separate responses: feelings, a behavior, a psychophysiological reac&on, and cogni&ve changes Amygdala amygdalae (singular amygdala) are small, almond-shaped structures in the medial temporal lobe adjacent to the anterior por&on of the hippocampus a collec&on of 13 nuclei that can be grouped into three main amygdaloid complexes The largest area is the basolateral nuclear complex, consis&ng of the lateral and basal nuclei, and accessory basal nuclei o lateral nucleus (La) receives sensory inputs o Connec&ons from the lateral nucleus to the basal nucleus (B), and from there to the ventral striatum, control the performance of ac&ons in the face of threat centromedial complex (Ce), which consists of the medial nucleus and the central nucleus o receives informa&on that has been processed in basal nuclei and forms a response. o connected to regions of the brainstem controlling innate emo&onal (or defensive) behaviors and their associated physiological (both autonomic and endocrine) responses smallest complex is the cor&cal nucleus (Co) o also known as the “olfactory part of the amygdala” because its primary input comes from the olfactory bulb and olfactory cortex o It outputs processing to the medial nucleus, as well as directly to the hippocampus and parahippocampus Klüver–Bucy syndrome was a lack of fear manifested by a tendency to approach objects that would normally elicit a fear response o observed deﬁcit was called psychic blindness because of an inability to recognize the emo&onal importance of events or objects extensive connec&ons to and from the amygdala suggest that it plays a cri&cal role in learning, memory, and aUen&on in response to emo&onally signiﬁcant s&muli has neurotransmiUer (glutamate, dopamine, norepinephrine, serotonin, and acetylcholine) and hormone receptors damage to the lateral amygdala prevents fear condi&oning. Without the amygdala, the evolu&onary value of fear is lost Inﬂuence of emo&on on learning Implicit emo&onal learning Fear condi&oning: neutral s&mulus acquires aversive proper&es when paired with an aversive event o Acquisi&on: ini&al stage of learning, when an uncondi&oned s&mulus evokes condi&oned response o A]er a few pairings of the light (CS) and the shock (US), the rat learns that the light predicts the shock, and soon the rat exhibits a fear response to the light alone àcondi&oned response CR o Ex&nc&on: unpair CS and resul&ng CR by presen&ng the CS alone without the aversive s&mulus àtakes many trials Amygdala lesions block the ability to acquire and express a CR to a neutral CS that is paired with an aversive US lateral nucleus of the amygdala serves as a region of convergence for informa&on from mul&ple brain regions, allowing for the forma&on of associa&ons that underlie fear condi&oning àsends projec&ons to the central nucleus cells in the superior dorsolateral amygdala have the ability to rapidly undergo changes, pairing the CS to the US. fear-inducing s&mulus reaches the amygdala through two separate but simultaneous pathways low road: goes directly from the thalamus to the amygdala without being ﬁltered by cogni&on or conscious control o cortex is bypassed, reach the amygdala rapidly (15 ms in a rat), though the informa&on is crude high road: sensory informa&on about the s&mulus is being projected to the amygdala via a cor&cal pathway o signiﬁcantly slower, taking 300 ms in a rat, but the cogni&ve analysis of the s&mulus is more thorough o sensory informa&on projects to the thalamus, which then sends the informa&on to the sensory cortex for a ﬁner analysis. o The sensory cortex projects the results of this analysis to the amygdala Explicit learning - Amygdala not necessary for explicit learning - Instructed fear paradigm: pa&ents with amygdala damage were able to learn and explicitly report that the blue square might be paired with a shock, but they did not show a startle repose to the blue square àdouble dissocia&on o Amygdala cri&cal for indirect expression of fear response when emo&onal learning occurs explicitly Amygdala, arousal, modula&on of memory - Flashbulb memories: autobiographic memories about what you did where you were when public event happened (like 9/11) àdetails forgoUen in a normal speed but conﬁdence in it remains high - Memory is enhanced by arousal àenhancement blocked by amygdala lesions - Amygdala modulates hippocampal, declara&ve memory by enhancing reten&on/ strengthening consolida&on at mul&ple stages - Bilateral amygdala damage: eﬀect of arousal on declara&ve memory for emo&onal events blocked - Unilateral damage: right amygdala most important - The more ac&ve amygdala, the stronger the memory - Acute stress can facilitate memory - Chronic stress impair memory with excessive hormone release ac&ng on the hippocampus Loca&onist approach - Emo&ons are categorical (0 -1) - Innate - Inherited through evolu&on - Each emo&on linked to a mo&va&onal state that triggers diﬀerent - ac&ons - Each emo&on is linked to dis&nct mechanisms in the brain and body - Emo&ons produced by ac&vity that speciﬁcally associated with a speciﬁc brain region / localiza&on - Same emo&on is consistently produced by the same brain ac&vity - Speciﬁcity: Amygdala à fear - Building blocks of emo&on: each emo&on associated with one building block (brain region) àif one building block is ac&vated, it will display the same emo&on every &me Construc&onist approach - Emo&ons emerge from basic psychological opera&ons / components - These psychological components are universal (not speciﬁc to emo&on) - ‘Emo&ons’ are not represented by the brain - The brain does not work based on categories - Large scale networks produce psychological events, not speciﬁc regions - Psychological func&on of a brain region is determined by what other regions (networks) are co-ac&vated - The same brain areas will be consistently ac&vated across instances from a range of emo&on categories Inﬂuence of emo&on on percep&on and aUen&on - AUen&onal blink paradigm: s&muli presented quickly, diﬃcult to iden&fy single s&muli - When aUen&onal resources are limited, awareness is reached by the amygdala through arousing emo&onal s&muli (has posi&ve or nega&ve valence) - Increased ac&vity in visual cortex to novel s&muli - Pa&ents with amygdala damage don’t show ac&va&on for fearful vs neutral faces in the visual cortex, pa&ents with hippocampus damage do Emo&on and decision making - Soma&c marker hypothesis: physiological arousal is needed to guide decision-making o Emo&onal reac&on manifests in our body as soma&c markers - Incidental aﬀect: current emo&ons indirectly aﬀect decisions o Emo&on role in decision making: act as informa&on, act as common currency between inputs and op&ons, focus aUen&on on new informa&on to guide decision, mo&vate approach or avoidance - Integral emo&on: emo&ons are incorporated into the decision o Gambling tasks: greater BOLD signal in amygdala for losses o Amygdala lesions reduce loss aversion OFC and decision-making - Integra&on of informa&on: associate situa&on with soma&c changes, integrate previous experience, evaluate response and es&mate risk / reward - Lesion to the OFC – diﬃculty an&cipa&ng consequences of ac&ons, learning from past mistakes - Iowa Gambling Task (Damasio): pa&ents with OFC damage perseverate on the bad decks àthey don’t learn from the fact that they are constantly losing

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