Biopsychology as a Neuroscience: Study Guide PDF

BIOPSYCHOLOGY AS A NEUROSCIENCE WHAT IS BIOPSYCHOLOGY? Biopsychology is the scientific study of how ➔​ Neuropathology - The study of nervous biology influences behavior. It focuses on how the...

BIOPSYCHOLOGY AS A NEUROSCIENCE WHAT IS BIOPSYCHOLOGY? Biopsychology is the scientific study of how ➔​ Neuropathology - The study of nervous biology influences behavior. It focuses on how the system disorders brain, nervous system, hormones, and genetics affect ➔​ Neuropharmacology - The study of the psychological functions like learning, memory, effects of drugs on neural activity emotion, and perception. This field is also known as ➔​ Neurophysiology - The study of the functions behavioral neuroscience or psychobiology, and activities of the nervous system emphasizing a biological approach to understanding psychological processes. What Are the Origins of Biopsychology? ​ Biopsychology became a major field in the 20th century. ​ The Organization of Behavior (1949) by D. O. Hebb was a key milestone. ​ Hebb’s theory linked brain activity to complex psychological functions (memory, emotions, perception). ​ His work combined experiments, clinical studies, and observations to support the idea that behavior is rooted in brain processes. ​ Biopsychology is still a young but rapidly growing scientific discipline. How Is Biopsychology Related to the Other Disciplines of Neuroscience? ​ Biopsychology is a key part of neuroscience, focusing on how the nervous system controls behavior. Biopsychologists bring expertise in behavior and research methods, making their contribution unique. Since the main function of the nervous system is to produce and regulate behavior, biopsychologists integrate knowledge from various neuroscience fields to better understand this connection. The following are a few of the disciplines of neuroscience that are particularly relevant to biopsychology (see Figure 1.2): ➔​ Neuroanatomy - The study of the structure of the nervous system. ➔​ Neurochemistry - The study of the chemical bases of neural activity ➔​ Neuroendocrinology - The study of interactions between the nervous system and the endocrine system  THE VISUAL SYSTEM 1.0 THE VISUAL SYSTEM HOW WE SEE? ○​ same image on the two retinas—is LIGHT ENTERS THE EYE AND REACHES THE greater for close objects than for RETINA distant objects; therefore, your ​ The light reflected into your eyes from the visual system can use the degree of objects around you is the basis for your binocular disparity to construct one ability to see them. three-dimensional perception from ​ Light can be thought of in two different ways: two two-dimensional retinal Photons or Waves of Energy images. ​ THE RETINA AND TRANSLATION OF Light is sometimes defined as waves of LIGHT INTO NEURAL SIGNALS electromagnetic energy between 380 and 760 ○​ After light passes through the pupil nanometers (billionths of a meter) in length and the lens, it reaches the retina. The retina converts light to neural signals, conducts them toward the ​ 2 properties of light: Wavelength and CNS, and participates in the Intensity processing of the signals. 1.1 PUPIL AND LENS ​ PUPIL ○​ The amount of light reaching the retinas is regulated by the irises. ○​ It enters the eye through the pupil. ○​ The adjustment of pupil size in response to changes in illumination represents a compromise between sensitivity and acuity. ○​ High level of illumination = constricting pupils ○​ Low level of illumination = dilated pupils ​ LENS ○​ Located behind pupil ○​ Near gaze = the lens refracts ​ The retina is composed of five different ○​ Distant gaze = the lens is flattened types of neurons: receptors, horizontal cells, ○​ The process of adjusting the bipolar cells, amacrine cells, and retinal configuration of the lenses to bring ganglion cells. images into focus on the retina is ​ Retinal neurons communicate both called accommodation. chemically via synapses and electrically via gap junctions. 1.2 EYE POSITION AND BINOCULAR DISPARITY ​ Retina is in a sense inside-out. ​ This inside-out arrangement creates two ​ One reason vertebrates have two eyes is that visual problems: One is that the incoming vertebrates have two sides: left and right. light is distorted by the retinal tissue through which it must pass before reaching the ​ BINOCULAR DISPARITY receptors. The other is that for the bundle of retinal ganglion cell axons to leave the eye, ○​ The difference in the position of the  there must be a gap in the receptor layer. FROM RETINA TO PRIMARY VISUAL CORTEX ​ The first of these two problems is minimized ​ By far the largest and most thoroughly by the FOVEA. studied visual pathways are the ​ It is the area of the retina that is specialized retina-geniculate-striate pathways, which for high-acuity vision. conduct signals from each retina to the ​ The blind spot, the second of the two visual primary visual cortex, or striate cortex, via problems created by the inside-out structure the lateral geniculate nuclei of the thalamus of the retina, requires a more creative solution which is COMPLETION. RETINOTOPIC ORGANIZATION ​ The visual system uses information provided ​ The retina-geniculate-striate system is by the receptors around the blind spot to fill retinotopic; each level of the system is in the gaps to your retinal images. organized like a map of the retina. SURFACE INTERPOLATION THE M AND P CHANNELS ​ the process by which we perceive surfaces. ​ Two parallel channels of communication flow through each lateral geniculate nucleus. CONE AND ROD VISION ​ Parvocellular layers (P Layers) ​ there are two different types of receptors in ​ Magnocellular layers (M Layers) the human retina: cone-shaped receptors called cones and rod-shaped receptors RECEPTIVE FIELDS: NEURONS OF THE called rods RETINA-GENICULATE-STRIATE SYSTEM ​ For most of the neurons in the DUPLEXITY THEORY OF VISION retina-geniculate-striate system, the ​ The theory that cones and rods mediate reaction—“on” firing or “off” firing—to a light different kinds of vision in a particular part of the receptive field was quite predictable. It depends on whether SPECTRAL SENSITIVITY they were on-center cells or off-center cell. ​ A graph of the relative brightness of lights of the same intensity presented at different RECEPTIVE FIELDS wavelengths is called a spectral sensitivity ​ The receptive fields of most primary visual curve. cortex neurons fall into one of two classes: ​ A photopic spectral sensitivity curve and a simple or complex. scotopic spectral sensitivity curve. The ​ Simple cells, like lower layer IV neurons, have photopic spectral sensitivity of humans can receptive fields that can be divided into be determined by having subjects judge the antagonistic “on” and “off” regions and are relative brightness of different wavelengths thus unresponsive to diffuse light. of light shone on the fovea. Their scotopic ​ Complex cells are more numerous than spectral sensitivity can be determined by simple cells. Like simple cells, complex cells asking subjects to judge the relative have rectangular receptive fields, respond brightness of different wavelengths of light best to straight-line stimuli in a specific shone on the periphery of the retina at an orientation, and are unresponsive to diffuse intensity too low to activate the few light. peripheral cones located there. ORGANIZATION OF PRIMARY VISUAL CORTEX PURKINJE EFFECT ​ Primary visual cortex was organized into ​ a phenomenon where the eye's peak functional vertical columns. sensitivity to light shifts towards the ​ The location of various functional columns in blue-green end of the spectrum as light the primary visual cortex is influenced by the levels decrease, causing reds to appear location on the retina of the column’s visual darker relative to other colors fields, by the dominant eye of the column, and by the column’s preferred straight-line EYE MOVEMENT angle. ​ Involuntary fixational eye movements are of ​ As Hubel and Wiesel’s studies progressed three kinds: tremor, drifts, and saccades. from retina, to thalamus, to lower layer IV of visual cortex, to simple cortical cells, to VISUAL TRANSDUCTION: THE CONVERSION OF complex cortical cells, the “preferences” of LIGHT TO NEURAL SIGNALS the neurons became more complex ​ Visual transduction is the conversion of light to neural signals by the visual receptors. 1.3 SEEING COLOR ○​ deficiency in the ability to see movement progress in a normal smooth fashion. COMPONENT THEORY (TRICHROMATIC THEORY) ​ Three different kinds of color receptors (cones), each with a different spectral sensitivity, and the color of a particular 2.0 MECHANISMS OF PERCEPTION stimulus is presumed to be encoded by the ratio of activity in the three kinds of ​ FEATURES OF SENSORY SYSTEM receptors. ORGANIZATION HIERARCHICAL ORGANIZATION OPPONENT- PROCESS THEORY ○​ The hierarchical organization of ​ There are two different classes of cells in the sensory systems is apparent from a visual system for encoding color and another comparison of the effects of class for encoding brightness. damage to various levels: The higher the level of damage, the COLOR CONSTANCY more specific and complex the ​ refers to the fact that the perceived color of deficit an object is not a simple function of the ○​ Functional segregation, Parallel wavelengths reflected by it. processing and summary model of sensory system organization. RETINEX THEORY ​ The visual system calculates the reflectance ​ AUDITORY SYSTEM of surfaces, and thus perceives their colors, ○​ The function of the auditory system by comparing the light reflected by adjacent is the perception of sound. surfaces in at least three different wavelength bands. ​ THE EAR ○​ Sound waves travel from the outer ear down the auditory canal and cause the tympanic membrane to vibrate. These vibrations are then ​ DIFFERENT CLASSES OF VISUAL CORTEX transferred to the three ○​ Primary Visual Cortex - area of ossicles—the small bones of the cortex that receives most of its middle ear: the malleus, the incus input from the visual relay nuclei of and the stapes. The vibrations of the thalamus. the stapes trigger vibrations of the ○​ Secondary Visual Cortex - receive membrane called the oval window, most of their input from the primary which in turn transfers the visual cortex vibrations to the fluid of the ○​ Visual Association Cortex - receive snail-shaped cochlea. The cochlea input from areas of the secondary is a long, coiled tube with an visual cortex as well as from the internal structure running almost to secondary areas of other sensory its tip. This internal structure is the systems. auditory receptor organ, the organ ​ DORSAL AND VENTRAL STREAMS of corti. ○​ DORSAL STREAMS - flows from the primary visual cortex to the dorsal prestriate cortex to the posterior parietal cortex. ○​ VENTRAL STREAMS - flows from the primary visual cortex to the ventral prestriate cortex to the inferotemporal cortex ○​ Where versus what theory of vision - damage to some areas of cortex may abolish certain aspects of vision while leaving others unaffected ​ AKINETOPSIA FROM THE EAR TO THE PRIMARY AUDITORY hierarchy, to areas of association cortex in CORTEX prefrontal and posterior parietal cortex ​ SOMATOSENSORY AGNOSIAS ○​ Astereognosis—the inability to recognize objects by touch. ○​ Asomatognosia—the failure to recognize parts of one’s own body. PERCEPTION OF PAIN ​ Pain is paradoxical ADAPTIVENESS OF PAIN ​ An experience that seems in every respect to be so bad is in fact extremely important for our survival LACK OF CLEAR CORTICAL REPRESENTATION OF PAIN ​ It has no obvious cortical representation DESCENDING PAIN CONTROL ​ AUDITORY CORTEX ​ Pain is that this most compelling of all ○​ Primate primary auditory cortex sensory experiences can be so effectively comprises three adjacent areas - suppressed by cognitive and emotional core region: belt and parabelt areas. factors. ​ ORGANIZATION OF PRIMATE AUDITORY CORTEX CHEMICAL SENSES: SMELL AND TASTE ○​ Primary auditory cortex is ​ Smell and taste are chemical senses. organized in functional columns. ○​ Auditory cortex is organized ADAPTIVE ROLES OF CHEMICAL SENSES tonotopically. ​ Molecules of food excite both smell and ○​ 2 large areas of association cortex: taste receptors and produce an integrated prefrontal cortex and posterior sensory impression termed flavor. parietal cortex ​ The main adaptive role of the chemical ​ DAMAGE TO AUDITORY SYSTEM senses is the evaluation of potential foods in ○​ Auditory Cortex damage natural environments, where potential foods ○​ Deafness in Humans prefrontal do not come with labels. ​ SOMATOSENSORY SYSTEM: TOUCH AND PAIN ○​ The system that mediates these OLFACTORY SYSTEM bodily sensations: exteroceptive, ​ The bodily structures that serve the sense of proprioceptive and interoceptive. smell. The system consists of the nose and ​ CUTANEOUS RECEPTORS the nasal cavities, which in their upper parts ○​ Free nerve endings, Pacinian support the olfactory mucous membrane for corpuscles, Merkel’s disks and the perception of smell and in their lower Ruffini endings. parts act as respiratory passages 2 MAJOR SOMATOSENSORY SYSTEM GUSTATORY SYSTEM ​ Dorsal Column Medial Lemniscus System ​ the sensory system that is partially tends to carry information about touch and responsible for the perception of taste. Taste proprioception is the perception stimulated when a ​ Anterolateral System tends to carry substance in the mouth reacts chemically information about pain and temperature. with taste receptor cells located on taste buds in the oral cavity, mostly on the tongue SOMATOSENSORY SYSTEM AND ASSOCIATION CORTEX BROAD TUNING VS NARROW TUNING ​ Somatosensory signals are ultimately ​ The archaic five-primary component conducted to the highest level of the sensory processing theory of taste implied that each  gustatory receptor and neuron is broadly ○​ Suggests that your brain can block tuned (responds to a wide range of tastes). from conscious awareness all However, the rapidly accumulating list of stimuli except those of a particular receptor molecules and mechanisms kind while still unconsciously suggests that each gustatory receptor is monitoring the blocked-out stimuli narrowly tuned (responds to only one taste, just in case something comes up or at least to very few of them). that requires your attention. ​ Anosmia and Ageusia ​ Simultanagnosia ○​ a difficulty in attending visually to more than one object at a time 2.1 SELECTIVE ATTENTION ​ Attention can be focused in two different ways: by internal cognitive processes (endogenous attention) or by external events (exogenous attention) ​ Cocktail Party Phenomenon  THE SENSORY MOTOR SYSTEM 1.0 THE SENSORY MOTOR SYSTEM ​ BASAL GANGLIA THREE PRINCIPLES OF SENSORIMOTOR ○​ group of structures near the center FUNCTION of your brain that form important connections. These connections allow different areas of your brain 1.​ Sensorimotor system is Hierarchically to work together. The basal ganglia Organized manage the signals your brain 2.​ Motor Output is guided by Sensory Input sends that help you move your 3.​ Learning changes the nature and locus of muscles Sensorimotor control ​ SCENDING MOTOR PATHWAYS ○​ Two pathways descend in the 1.1 SENSORIMOTOR ASSOCIATION CORTEX dorsolateral region of the spinal cord—collectively known as the dorsolateral motor pathways, and 2 MAJOR AREAS: two descend in the ventromedial ​ POSTERIOR PARIETAL ASSOCIATION region of the spinal CORTEX cord—collectively known as the ○​ plays an important role in ventromedial motor pathways. integrating two kinds of Signals conducted over these information, directing behavior by pathways act together in the control providing spatial information, and in of voluntary movement directing attention ​ SENSORIMOTOR SPINAL CIRCUITS ​ DORSOLATERAL PREFRONTAL ○​ The motor circuits of the spinal ASSOCIATION cord show considerable complexity ○​ It receives projections from the in their functioning, independent of posterior parietal cortex, and it signals from the brain. sends projections to areas of ​ CENTRAL SENSORIMOTOR PROGRAMS secondary motor cortex, to primary AND LEARNING motor cortex, and to the frontal eye ○​ all but the highest levels of the field. sensorimotor system have certain patterns of activity programmed ​ SECONDARY MOTOR CORTEX into them, and complex movements ○​ those that receive much of their are produced by activating the input from the association cortex appropriate combinations of these and send much of their output to programs the primary motor cortex. ○​ PRIMARY MOTOR CORTEX ​ It is the major point of CENTRAL SENSORIMOTOR PROGRAMS AND convergence of cortical LEARNING sensorimotor signals, and ​ all but the highest levels of the sensorimotor it is the major, but not the system have certain patterns of activity only, point of departure of programmed into them, and complex sensorimotor signals from movements are produced by activating the the cerebral cortex. appropriate combinations of these programs ​ CEREBELLUM ​ CHARACTERISTICS ○​ receives information from primary ○​ Central Sensorimotor Programs Are and secondary motor cortex, CAPABLE Of Motor Equivalence information about descending ○​ Sensory Information That Controls motor signals from brain stem Central Sensorimotor Programs Is motor nuclei, and feedback from Not Necessarily Conscious motor responses via the ○​ Central Sensorimotor Programs somatosensory and vestibular Can Develop Without Practice. systems. ○​ Practice Can Create Central Sensorimotor Programs.  THE NERVOUS SYSTEM 1.1 THE NERVOUS SYSTEM FIVE PHASES OF NEURODEVELOPMENT ○​ Passive cell death is called ​ ZYGOTE necrosis; active cell death is called ○​ First, cells must differentiate. apoptosis. ○​ Second, cells must make their way ○​ During the period of cell death, to appropriate sites and align neurons that have established themselves with the cells around incorrect connections are them to form particular structures. particularly likely to die. ○​ Third, cells must establish appropriate functional relations ​ POSTNATAL CEREBRAL DEVELOPMENT IN with other cells. HUMAN INFANTS ○​ There is a general increase in TOTIPOTENT, PLURIPOTENT, MULTIPOTENT, UNIPOTENT. synaptogenesis in the human cortex shortly after birth, but there ​ Induction of Neural Plate are differences among the cortical ○​ The development of the neural plate regions. is the first major stage of neurodevelopment in all vertebrates ​ DEVELOPMENT OF THE PREFRONTAL ​ Neural Proliferation CORTEX ○​ does not occur simultaneously or ○​ As you have just learned, the equally in all parts of the tube. prefrontal cortex displays the most ​ MIGRATION AND AGGREGATION prolonged period of development of ○​ During this period of migration, the any brain region. Its development is cells are still in an immature form, believed to be largely responsible lacking the processes (i.e., axons for the course of human cognitive and dendrites) that characterize development mature neurons. ○​ Radial Migration, Tangential ​ EFFECTS OF EXPERIENCE ON POSTNATAL Migration. DEVELOPMENT OF NEURAL CIRCUITS ○​ There are two methods by which ○​ Permissive experiences are those developing cells migrate: Somal that permit the information in Translocation and Glia-Mediated genetic programs of brain Migration development to be expressed and maintained. Instructive experiences ​ Once developing neurons have migrated, are those that contribute to the they must align themselves with other information in genetic programs developing neurons that have migrated to and influence the course of the same area to form the structures of the development. nervous system. ​ CRITICAL PERIODS VS SENSITIVE PERIODS ​ AXON GROWTH AND SYNAPSE ○​ If it is absolutely essential (i.e., FORMATION critical) for an experience to occur ○​ Once neurons have migrated to within a particular interval to their appropriate positions and influence development, the interval aggregated into neural structures, is called a critical period. If an axons and dendrites begin to grow experience has a great effect on from them. development when it occurs during ○​ Once axons have reached their a particular interval but can still intended sites, they must establish have weak effects outside the an appropriate pattern of synapses. interval, the interval is called a sensitive period ​ NEURON DEATH AND SYNAPSE ARRANGEMENT ​ COMPETITIVE NATURE OF EXPERIENCE NEURODEVELOPMENT: OCULAR DOMINANCE COLUMNS AND ○​ Manipulations of early experience have become more selective. This competitive aspect is clearly illustrated by the disruptive effects of monocular deprivation on ocular dominance columns in the primary visual cortex. ​ NEUROPLASTICITY IN ADULTS ○​ Neuroplasticity was once thought to be restricted to the developmental period ○​ Neurogenesis in Adult Mammals. ​ DISORDERS OF NEURODEVELOPMENT: ○​ Autism Spectrum Disorder ○​ Williams Syndrome  FOUNDATION OF BIOPSYCHOLOGY 1.0 What Types of Research Characterize the 1.1 EXPERIMENTS AND NON EXPERIMENTS Biopsychological Approach? ​ Experiments: Used to study cause and effect ​ Biopsychology is a broad field within by manipulating an independent variable and neuroscience that studies various topics measuring its effect on a dependent using different research methods. Research variable. Researchers ensure no other can vary in three ways: it may use human or factors (confounding variables) interfere. nonhuman subjects, be experimental or Example: Lester & Gorzalka study on the nonexperimental, and focus on pure Coolidge effect in hamsters. (theoretical) or applied (practical) research. ​ Nonexperimental Studies: Used when experiments are not possible. Two common Human and Nonhuman Subject types: ○​ Quasi-experimental studies – Compare groups without direct ➔​ Both humans and animals (mice, rats, cats, control over variables. dogs, primates) are used in research. ○​ Case studies – In-depth analysis of individuals or small groups, useful ​ Humans are preferred because they: for rare conditions. ○​ Have human brains (most relevant for understanding human function). QUASI-EXPERIMENTAL STUDIES & CASE STUDIES ○​ Can follow instructions and report experiences. ​ Quasi-Experimental Studies ○​ Are often cheaper than maintaining ○​ Used when true experiments are not animal labs possible due to ethical or practical ​ Animals are valuable because: limitations. ○​ The brain differences between ○​ Involves studying groups already species are quantitative, not exposed to certain conditions in qualitative. real life (e.g., alcoholics vs. ○​ Studying them helps clarify non-drinkers). universal principles of brain ○​ Limitations: No control over function. confounding variables, so results may not show clear causation. WHAT ETHICAL CONSIDERATIONS SHOULD ​ Case Studies GUIDE BIOPSYCHOLOGICAL RESEARCH ON ○​ In-depth study of a single individual NONHUMAN ANIMALS? or case. ○​ Useful for generating testable ​ Strict Ethical Guidelines – Research on hypotheses and understanding rare animals follows strict ethical codes set by conditions.​ independent committees. ​ Humane Treatment – Biopsychologists 1.2 COMPARISON OF PURE AND APPLIED ensure the well-being and care of animals in RESEARCH experiments. ​ Justification for Use – Animal research is ​ Pure Research only conducted when necessary and when it ○​ Conducted out of curiosity to provides valuable insights into brain expand knowledge. function. ○​ Focuses on fundamental principles ​ Minimizing Harm – Researchers aim to without immediate practical reduce pain and distress, using alternatives application. whenever possible. ○​ May lead to unexpected real-world ​ Respect for Life – Since animals help us benefits over time. understand human behavior, they must be ○​ More vulnerable to funding cuts due treated with respect and care. to its lack of immediate benefits. ​ Applied Research ○​ Aimed at solving practical problems and benefiting society.  ○​ Uses existing knowledge to develop treatments, technologies, or solutions. ○​ Often receives more funding due to its clear impact on society.. KEY TAKEAWAYS:. While pure and applied research serve different purposes, pure research often leads to applied discoveries, and many studies combine both approaches.