Psychology Notes PDF

What is Psychology Psychology is the science of human behavior and mental processes. It studies behavior and the physiological and cognitive processes that underlie it. Monday, December 26, 2022 Psychiatry Department 1 Monday, December 26,...

What is Psychology Psychology is the science of human behavior and mental processes. It studies behavior and the physiological and cognitive processes that underlie it. Monday, December 26, 2022 Psychiatry Department 1 Monday, December 26, 2022 Psychiatry Department 2  Perspectives of psychology 1. Biological perspective An orientation toward understanding the neurobiological processes that underlie behavior and mental processes. 2. Behavioral perspective An orientation toward understanding observable behavior in terms of conditioning and reinforcement. 3. Cognitive perspective An orientation toward understanding mental processes such as perceiving, remembering, reasoning, deciding, and problem solving and their relationship to behavior. 4. Psychoanalytic perspective An orientation toward understanding behavior in terms of unconscious motives stemming from sexual and aggressive impulses. 5. Subjectivist perspective An orientation toward understanding behavior and mental processes in terms of the subjective realities people actively construct. Monday, December 26, 2022 Psychiatry Department 3  Major fields of psychology 1- Biological psychology: discover the relationship between 6- Counseling psychology: work with high school or biological processes and behavior. university students providing help with problems of 2- Experimental psychology: use experimental methods to social adjustment and vocational and educational goals. study how people react to sensory stimuli, perceive the 7- School and educational psychology: work with world, learn and remember, …. individual children to evaluate learning and emotional 3-Developmental psychology: concerned with human problems, intelligence, achievement and personality. development and factors that shape behavior from birth to old age. 8. Industrial and engineering psychology: concerned 4. Social psychology: interested in the ways of interactions with selecting people for jobs, training programs, with other people, which influence attitude and behavior motivation of employees… 5- Clinical psychology: apply psychological principles to the 9. Forensic psychology: Psychologists who work within diagnosis and treatment of emotional and behavioral the legal and judicial systems. problems, mental illness, juvenile delinquency, criminal behavior, drug addiction, mental retardation, marital and 10- Cognitive psychology: concerned with people’s family conflict and other adjustment problems. internal mental processes, such as memory, language and thought.  Thinking & Language Thinking: ‘It is a mental activity that goes on in the brain when a person is organizing and attempting to understand information and communicating information to others. Brain areas concerned with thinking include, cerebral cortex, limbic system and reticular activating system Concepts: are mental event used to represent a category or class of events or objects. It represents categories, classes or groups of things not just single individual cases (it is the tool of thinking). Types: 1- Formal concept: These have rigid rules or features that define a particular concept. Example: Categories for solid, liquid or gas 2- Natural concept: These are concepts people form as a result of their real-world experience Acquiring Concepts: - Inborn Concepts: As the concept of “time” and “space” , - Learned Concepts: It can either be explicitly taught or learned by experience Phases of Concept Formation 1- Generalization: Inability to discover differences between familiar and unfamiliar objects. It occurs usually during the first three years of life. 2- Differentiation: Making distinction between different items. Usually this phase extends along childhood period. 3- Abstraction: It is the ability to grasp the essentials of a whole, to break the whole into its parts, and to discern common properties. Types of Thinking : 1- Imaginative (Autistic) Thinking: It is unrealistic, uncontrolled thinking, not goal directed, does not need attention, does not lead to exhaustion ex. Imaginative play, daydream. 2- Controlled or purposive Thinking: It is a creative type of thinking and can be logic and goal directed.  Phases of purposive thinking: a) Preparation - Recognizing the problem. - Defining the goals. b) Information gathering - Collection of data related to the problem c) Solving state: -Elimination of the non-essential information and irrelevant solution. -Choosing the most appropriate solution. -Putting the different and alternative solutions. - Use of different strategies for solving problems. d)Evaluation: Assessment of results/Criticism. Problem solving: It is an active intellectual or cognitive process requires manipulation of cognition to resolve a problem. It is one of the highest cognitive processes Strategies for Problem Solving: 1)Trial and Error ▪ Problem solving method in which one possible solution after another is tried until a successful one is found. 2)Algorithms ▪ A systematic step-by-step method of trying every possible solution. 3) Heuristics Heuristics are simple thinking strategies in which generating and testing hypothesis that may solve the problem in a sensible organized way. An educated guess based on prior experience that helps narrow down the possible solutions for a problem. less time consuming, but more error-prone than algorithms. e.g. to reach a case diagnosis: what common is common 4) Reduction strategy -This can be done by cutting complex problem down into parts then fixing each part, At the end the problem will be fixed. 5) Finding analogue -An analogy is a similarity between two or more items, events or situations. 6) Creative thinking -Creativity is the ability to produce valued outcomes in a novel way. Creative Problem-Solving Stages 1. Preparation: - The basic elements of the problem are considered. - Past experience becomes relevant but should not become restrictive. 2. Incubation: In this stage, the problem is put away for a while and not thought about. Perhaps unconscious process can be brought to bear on the problem. 3. Illumination: This is the most mysterious stage of the problem-solving process. Like insight, a potential solution to a problem seems to materialize from nowhere. 4. Verification: Now the proposed solution must be tested (or verified). Divergent thinking (ability to produce many alternatives or ideas) is linked to creativity. Convergent thinking (attempting to find one correct answer) is linked to conventional, non-creative thinking (e.g., 2 + 2 = ?).  Key Barriers to Problem Solving: 1. Mental Sets: Persistence use of strategies that have worked in the past even if no longer appropriate 2. Functional Fixedness: - It is a type of mental set in which an object is seen as serving a few fixed functions. i.e. Thinking of an object as only functioning in its usual way 3. Confirmation Bias - Preferring information that confirms preexisting positions or beliefs, while ignoring contradictory evidence Language: It is a system of combining symbols (such as words) for expressing or communicating thoughts and feelings among two or more individuals using the same language. Language Components: A) Phonology - The patterns of basic speech units and the accepted rules of pronunciation. - The basic building blocks of language. B) Morphology -The study of the smallest meaningful units of speech (morphemes). - May be a word or a part of a word (such as a prefix, e.g., pill and kill are morphemes. C) Syntax How individual words and basic meaningful units are combined to create sentences. D) Semantics -The ways in which a language conveys meaning. E) Pragmatics -The contextually appropriate use of language. - The manner in which speakers communicate their intentions depends on the social context. Explaining Language Development - Childhood is a critical period for fully developing certain aspects of language. - Children never exposed to any language (spoken or signed) by about age 7 gradually lose their ability to master any language. 1- Operant Learning: Skinner believed that language development may be explained on the basis of learning principles such as association, imitation, and reinforcement. 2. Inborn Universal Grammar: Chomsky opposed Skinner’s ideas and suggested that the rate of language acquisition is so fast that it cannot be explained through learning principles, and thus most of it is inborn and all children, regardless of their intellectual ability, become fluent in their native language within five or six years. Chomsky believes that every child has a ‘language acquisition device’ or LAD, which encodes the major principles of a language and its grammatical structures into the child’s brain.  Developmental Milestones of Language The year The development First year - Babbling Stage (3 to 4 months) - The stage of speech development in which the infant spontaneously utters various sounds (i.e., phonemes). - They begin to speak one word by 12 months of age 1-2 years They have vocabulary of 25 words. 3 years - They combine sentences of 2 words. - There is increase in the vocabulary without grammatical rules. 4 years and The children can use grammatical rules. over Memory & Intelligence Memory is the cognitive ability and constructive process that acquires, encodes, stores and retrieves information. Encoding is an automatic process and happens without our awareness. It is the modification of information to fit the preferred format for the memory system. Semantic Encoding; meaning of words Acoustic Encoding; of sounds Visual Encoding; of pictures, images Storage is the process of holding or retention of encoded information in memory over time. The way we store information affects the way we retrieve it. Three stages of memory – Sensory Memory – Short-term memory – Long-term Memory Retrieval is the process of recovery the information, which is stored in memory (remembering). Retrieval clues are the search terms we use to activate memory. The more specific you are, the better the results will be. Memories can be cued in two ways: Recall: a retrieval method in which one must reproduce previously presented material. Recognition: a retrieval method in which one must identify information that is provided, which has previously been presented. Neurobiology of memory: - Anatomical areas involved in memory include, Hippocampus,Amygdala,Temporal Lobe, Medial Frontal Gyrus, Mammillary Bodies - Neurotransmitters involved in memory: Acetyl choline, Serotonin,Dopamine, Nor- Epinephrine, Some Neuropeptides, Others (protein, DNA, RNA) Types of Memory: A- Sensory Memory: Hold large amounts of information, Registered at the sensory receptors (auditory, visual..) Very brief period; visual< auditory -It is based on electrical changes -e.g. Visual Stimulation-Iconic memory, Auditory Stimulation-Echoic memory B- Short Term Memory (STM): Limited capacity (7±2 bits of information). Limited duration (15-20 seconds). Limited storage. we have to pay attention to the information process. Forgetting occur by decay or displacement. Information in STM could pass to long-term memory LTM rehearsal or consolidation. It is based on chemical changes reverberating circuits. C- Long Term Memory: Unlimited capacity,Very Long duration, Permanent but subjected to distortion or replacement. It is stored and retrieved by association. Organizing information can help and aid retrieval. Long term memory is based on: Neurotransmitters (Acetyl choline mainly), Formation of new circuits, Protein synthesis involvement of RNA, DNA. Types of long term memory : A- Procedural memory (non declarative): is a apart of LTM that is responsible, for knowing how to do things i.e. memory of motor skills B- Semantic memory (declarative): is a part of LTM that is responsible for storing information about the world. This includes knowledge about the meaning of words as well as general knowledge. C- Episodic memory (declarative): : is a part of the LTM responsible for storing information about events (i.e. episodes) that we have experience in our lives.  Causes of Forgetting: 1- Interference: Proactive interference: when an old memory makes it more difficult to remember a new memory. Retroactive interference: when new information interferes with the ability to remember previously learned information. 2- Repression: It is called motivated forgetting. It occurs when anxiety producing or traumatic events are forced into the unconscious level of the mind. 3- Failure of encoding: one reason that we forget is because we fail to encode the information so that the information never entered the LTM for example old age. 4- Failure of registration: Failure of consolidation and storage of the learned materials. It may be due to head trauma or under effect of drugs. 5- Failure of retrieval: depends on emotional and physical state, interest and psychological state as well. Disorders of Memory : Amnesia: partial or total inability to recall past experience. Psychogenic amnesias Organic amnesia Memory Assessment Scales: The Wechsler Memory Scale (WMS) (age 16 through 90) Intelligence -It is the general ability to solve intellectual problems on basis of past learning and present grasp of essentials or the ability to solve problems and to cope with environment. Theories of Intelligence 1- Charles Spearman; General Intelligence, intelligence is general cognitive ability that could be measured and numerically expressed. He viewed intelligence as a single general ability 2- Louis Thurstone (Primary Mental Abilities): Instead of viewing intelligence as a single general ability, he focused on seven different "primary mental abilities.“ 1. Verbal comprehension: ability to understand words. 2. Word fluency: ability to think of words rapidly. 3. Number : the ability to do mathematic problems. 4. Space: the ability to understand spatial relationship. 5. Rote memory: ability to memorize and recall. 6. Perceptual: grasp similarities, differences and details of objects. 7. Reasoning: ability to understand principles of problem solving. General factors: linking all characteristics 3- Howard Gardner- Multiple Intelligences: describes eight distinct intelligences that are based on skills and abilities that are valued within different cultures. The eight intelligences Gardner described are: Visual-spatial Intelligence, Verbal- linguistic Intelligence, Bodily-kinesthetic Intelligence, Logical-mathematical Intelligence, Interpersonal Intelligence, Musical Intelligence, Intrapersonal Intelligence, Naturalistic Intelligence. 4- Robert Sternberg: defined intelligence as "mental activity directed toward purposive adaptation to, selection and shaping of, real-world environments relevant to one’s life." While he agreed with Gardner that intelligence is much broader than a single, general ability, he instead suggested some of Gardner's intelligences are better viewed as individual talents. Sternberg proposed what he refers to as 'successful intelligence,' which is comprised of three different factors: Analytical intelligence: refers to problem-solving abilities. Creative intelligence: involves the ability to deal with new situations using past experiences and current skills. Practical intelligence: refers to the ability to adapt to a changing environment. Intelligent Quotient Calculation (IQ): It was first coined by William Stern, it is mental age divided by chronological age multiplied by 100. - Mental age: is the score obtained by a child who passes all the test items which are normally passed by the average ability child of his age. - Chronological age: actual age. Growth of intelligence: This continues throughout childhood. It increases progressively till age of 15 years, then more slowly till the age of 18 years. All psychologists recognize that both genetics and the environment play a role in determining intelligence. Hereditary is responsible for 70% of intelligence, while environment factors affect 30% of intelligence. Enrichment the environment will lead to general increase in levels of intelligence by about 20-30 points. Intelligence Tests: Stanford Binet test (2-18 yrs.), The Wechsler Intelligence Scale for children (5-15 years) The Wechsler preschool Intelligence Scale for children (below 5 years), The Wechsler Adult Intelligence Scale (WAIS) is a test designed to measure intelligence in adults and older adolescents. Group difference in intelligence: Sex: females do relatively better in tests involving language; males do relatively better in mathematical tests. Race: no difference. Country and city children: slight superiority of IQ in city children. Uses of intelligence tests: Educational purpose: to direct according to abilities. Vocational guidance: to select employers to certain jobs. Measurement of level of intellectual impairment in certain diseases. Marital counseling Check effect of therapy on intellectual abilities. Abilities Achievement: measure present abilities by which we can achieve. It is the actual ability. Capacity: measure individual ability, which is hidden. It is potential ability. Aptitude: it is predictive ability. Special abilities: some people have normal intelligence, but an outstanding ability in math (arithmetic prodigies).  Psychology of Learning The process by which experience produces a relatively permanent change in an organism’s behavior or abilities. Learning leads to change in thinking, emotions and behavior. Approaches to learning I- Behavioral theories: Focus only on the objectively observable aspects of learning. They fall under two broad categories of S-R theory (stimulus- response) 1- S-R (Stimulus-Response) theory without reinforcement Pavlov- Classical Conditioning 2- S-R (Stimulus-Response) theory with reinforcement Thorndike- Trial and Error theory Skinner- Operant Conditioning Pavlov- Classical Conditioning S-R theory without reinforcement The Russian psychologist Ivan Pavlov introduced classical conditioning through his experiments on dogs. Pavlov showed how a reflex (salivation, a natural bodily response to food) could become conditioned (modified) to an external stimulus (the bell) thereby creating a conditioned reflex/response. The Unconditioned Stimulus (UCS): It can evoke a response without prior learning or conditioning. For example, when a dog eats some food it causes his mouth to salivate. Therefore, the food is an unconditioned stimulus. Conditioned Stimulus (CS): Is created by learning, and therefore does not produce a response without prior conditioning. For example, if dogs had not learnt to associate the bell with food, they would not salivate when the bell rings. Conditioned Reflex (CR): Is a response that was learnt by associating it with an unconditioned stimulus. For example; salivation in response to hearing the bell WITHOUT any food. Phenomena occurring in classical conditioning Extinction: A conditioned response will disappear over time when the conditioned stimulus is no longer presented. Spontaneous recovery: Sometimes there is the weak appearance of a previously extinguished response. Stimulus generalization:This is when individuals respond in this same way to experience stimuli. For example, all fuzzy animals scaring a young child instead of just a fuzzy cat. Stimulus discrimination: Organisms can learn to discriminate between various stimuli. S-R theory with reinforcement Trial and Error Theory of Learning Thorndike says that learning takes place when a person makes a number of trials, some responses do not give satisfaction to the individual, but he goes on making further trials until he gets satisfactory responses. Learning takes place because of formation of an association between stimulus and response.  S-R theory with reinforcement Operant conditioning Operant conditioning (instrumental conditioning) is a method of learning that occurs through rewards and punishments for behavior. Through operant conditioning, an association is made between a behavior and a consequence for that behavior. Skinner used the term Operant to refer to any "active behavior that operates upon the environment to generate consequences" Skinner introduced a new term- Reinforcement. Behaviour that is reinforced tends to be repeated (i.e. strengthened); behaviour that is not reinforced tends to die out-or be extinguished (i.e. weakened). A reward is something, which has value to the person giving the reward, but may not necessarily be of value to the person receiving the reward. A reinforcer is something, which benefits the person receiving it, and so results in an increase of a certain type of behavior  Types Of Responses Neutral response: Responses from the environment neither increase nor decrease the repetitions of behavior Reinforcers: Any event that increases the behavior it follows. There are two kinds of reinforcers: Positive reinforcers Favorable outcomes that are presented after the behavior. I.e. behavior is strengthened by the addition of something positive as praise or a direct reward behavior. Negative reinforces Removal of an unfavorable events or outcomes after the display of a behavior. In these situations, a response is strengthened by the removal of something considered unpleasant, e.g.removal from detention list for students. In both of these cases of reinforcement, the behavior increases. Punishment Is the presentation of an adverse outcome that causes a decrease in the behavior it follows. Punishment weakens behaviour. Schedules of Reinforcement Continuous reinforcement - reinforcement is given every time the one gives the desired response. Intermittent reinforcement - reinforcement is given only part of the times the one gives the desired response. Ratio reinforcement - a pre-determined proportion of responses will be reinforced. Fixed ratio reinforcement - reinforcement is given on a regular ratio, such as every fifth time the desired behavior is produced. Variable ratio reinforcement (random)- reinforcement is given for a predetermined proportion of responses, but randomly instead of on a fixed schedule. Interval reinforcement- reinforcement is given after a predetermined period of time. Fixed interval reinforcement - reinforcement is given on a regular schedule, such as every five minutes. Variable interval reinforcement - reinforcement is given after random amounts of time have passed Skinner found that continuous reinforcement in the early stages of training seems to increase the rate of learning. Later, intermittent reinforcement keeps the response going longer and slows extinction. Cognitive theory of learning Learning has been considered partly a cognitive process and partly a social and affective one. It qualifies as a cognitive process because it involves the functions of attention, perception, reasoning, analysis, drawing conclusions, making interpretations and giving meaning to the observed phenomena. Cognitive learning involves acquisition of knowledge or understanding. Application of learning theories: Aversion therapy in addiction and sexual paraphilia. Systematic desensitization in phobias. Shaping and chaining in mental retardation. Positive reconditioning in nocturnal enuresis. Experimental deconditioning in tics.  Emotions Emotion is any conscious experience characterized by intense mental activity and a certain degree of pleasure or displeasure. Functions of emotions: Increase, decrease, or regulate arousal. Direct perception and attention. Influence learning and memory. Organize and motivate behavior. Communicate with others. Components of Emotions The Subjective Experience: While experts believe that there are a number of basic universal emotions that are experienced by people all over the world regardless of background or culture, researchers also believe that the experience of emotion can be highly subjective. The physiological response: The physical reactions experienced during an emotion such as sweating palms, racing heartbeat, or rapid breathing are controlled by the sympathetic nervous system, which is charged with controlling the body's fight-or-flight reactions. The behavioral response: The final component is the actual expression of emotion. The ability to accurately understand these expressions is tied to our emotional intelligence and these expressions play a major part in our overall body language. Variety of Emotions: Positive Human Emotions Negative Human Emotions  Factors affecting emotions include: 1- Personality 2- Culture 3- Weather 4- Stress 5- Age 6- Gender 7- Environmental 8- Marital relations 9- organizational 10- Social The neuroscience of emotions: Several areas of the cortex also are important in emotion, including the prefrontal cortex, posterior cortex, and insula. 1. Right hemisphere: High activity is associated with depression. Damage often leaves individuals emotionally indifferent and unable to read many emotions. 2. Left hemisphere: More active than right during smiling, positive emotions, and relatively low activity in the left frontal lobe is associated with depression. The neuroendocrinology of emotions: I. The hypothalamic-pituitary-adrenal system controls stress hormones that facilitate short-term coping with emotional events, through Hypothalamus: Brain region that regulates hormonal functions via the pituitary gland.  Pituitary gland: “Master gland” that receives messages from hypothalamus and relays signals to endocrine glands to regulate hormones. Adrenal glands: Located atop the kidneys; top part (adrenal cortex) responds to signals from pituitary by releasing stress hormones such as cortisol into the blood. Autonomic Nervous System controls responses to cognitive and environmental stimuli that give rise to emotional responses. Neurotransmitters of emotions: They include: serotonin, norepinephrine and dopamine Neuropeptides include: GABA and excitatory neurotransmitters as glutamte  Classification of Emotions: Internalized (based on internal stimuli e.g. depressed mood) Externalized (based on external stimuli e.g. anger) 1- Cognitive (based on cognitive activity such as judgment), 2- Affective (based on explanations of feelings or emotional experiences) and 3- Somatic (based on bodily experiences). Examples: ▪ Anxiety (cognitive)- Fear (feeling component), rapid heartbeats (bodily reaction) Theories of emotions: Most theories of emotion are based on physiology, thought, and the actual emotion.  Cannon-Bard theory: Walter Cannon coined the phrase "fight or flight". -- Walter Cannon and Philip Bard worked together to develop the Cannon-Bard theory of emotion. They believed emotions come first and physical reactions come second. James-Lange theory: It is the opposite of the Cannon-Bard theory. This theory states that an individual has a physiological response to a stimulus first, and then experiences an emotion based on his or her interpretation of the physiological response. Sigmund freud: Mental illness came from repressed emotions in the unconscious mind. Freud believed that release and acceptance of these denied or repressed emotions and memories were vital for mental health. If this emotional energy was not released, Freud noted that it led to physiological symptoms and illnesses. He termed these physiological manifestations of emotions "psychosomatic." Severe psychosomatic cases of repressed memories of trauma led to a diagnosis of "hysteria."  Klaus Scherer Scherer’s theory The Component Process Model (CPM), consists of 5 sub- systems of an emotion. Scherer stated that these subsystems did not work independently of each other but were part of a collaborative process. These subsystems are cognitive appraisal, physiological arousal, motoric system (including facial expression), subjective feeling, and motivational system. Robert Plutchik Created a wheel of emotions in 1980, which consisted of 8 basic emotions and 8 advanced emotions each composed of 2 basic ones. He illustrated the relationships of one emotion to another in a wheel diagram The 8 basic categories of emotions are anger, fear, sadness, disgust, surprise, anticipation, acceptance, and joy. Plutchik believed that the purpose of emotions was to create an interaction between the individual and the stimulus (an event or person) in such a way that the emotion could be resolved to bring the person back to equilibrium.  Attention and Perception Attention: It is the ability to focus our awareness on some stimuli while ignoring others. Characteristics of attention: 1- Attention span: The time you can sustain attention Measured by digit subtraction or days of week inversely 2- Attention field: The number of stimuli that you can pay attention to at the same time Measured by digit 7+2 3- Attention focus: The ability to discriminate between stimulus and background. 4- Adaptability: If you focus for a long time on one stimulus this leads to adaptation i.e. ↓ attention. 5- Attention shift: To avoid the adaptation attention shifts from one focus to another (attention isn't static).  Types of attention: 1- Involuntary attention: Involuntary direction of our attention towards the stimulus e.g. gunshot or a flash of light (stimulus related). 2- Voluntary attention: The ability to sustain inner mental operation intentionally without disputation e.g. listening to a lecture (personal related). 3- Spontaneous attention: It is non-conscious effort that made for awareness when the stimulus is interesting e.g. watching an action movie. 4- Habitual attention: The ability to focus on specific stimulus out of a related experience and mental set e.g. the neurologist who observe personal gait  Neuroanatomical basis of attention: 1- Reticular formation (RAS): for arousal state, activation and filtering of stimuli so that the cortex doesn't become loaded with stimuli. 2- cerebral cortex: Inferior Parietal , Orbital Frontal , Dorso-lateral and Medial Frontal Lobe A- Voluntary awareness of different stimuli. B- Focused attention C- Sustained attention D- Response control; switching or shift 3- Limbic System: A- establishes salience, whereby determining priority of incoming stimuli so, limits of attention C- hippocampus: memory encoding and retrieval constrain attention). 4- Subcortical System: A- relay of sensory input through thalamus B-caudate nucleus: selection of motor responses and coordination of sensory information. Models of Attention: 1- Bottom-up modulation: – Reticulo-thalamo-cortical pathway- cortical arousal by passing sensory information through thalamus towards cortex –Extra-thalamic pathways from brainstem and basal forebrain to cortex Global influence on attention without selectivity for sensory modality or cognitive domain 2- Top-down modulation “parietal, limbic, prefrontal cortex” (right hemi preference) – frontal important in processing novel information, sustain attention and shift. – Limbic lobe important for salience, mood and motivational factors Factors affecting attention: A- External (important in the art of advertising) -Type of stimulus, Position of stimulus: upper half > lower, Contrast of stimulus, Intensity of stimulus, Changeability, Repetition of stimulus B- Internal (individual related) Biological needs, Emotional state, Motives, Mental set Factors decreasing attention: Internal factors: Physical: fatigue, lack of sleep, malnut, social: family troubles, psychological: amotivation, daydreams, obsessions, psychiatric: delusion, hallucination, thought disorder 2- External factors: Light, noise, temperature of environment Perception: It is an active mental process of transferring a sensory stimuli into psychological information (interpretations of sensory stimuli into meaning). i.e. cognitive response to sensory input Perception depends on: 1- past experience…..importance of memory/ cognitive schemata 2- present stimulus 3- future expectation…...so, we perceive things as we are not as they are Perception Sensation Giving interpretations to The act of receiving stimuli by stimuli sensory organs Secondary association areas Primary sensory areas (Parietotemporal) (Parietal lobe) active Passive Psycho-physiological Physiological (neuropsychological) Variable Universal  Functions of the perceptual system: 1- Recognition of objects. 2- Localization of objects. 3- Perceptual constancy. 1- Selectivity: It is the first part of the perception process, in which we pay our attention on certain incoming sensory information. It is mediated through reticular formation in the brain stem Value of selection: 1- it is so difficult to perceive 2 stimuli through the same sensory organ at the same time. But we can perceive more than one stimuli but of different modalities 2- to save the rest of our information processing talents to the best possible advantage. Factors affecting perceptual selectivity: 1- Contrast: the most important stimulus factor is the extent to which a given stimulus is different from other stimuli around it (background).e.g. size, intensity, position, motion 2- Changeability:Perception is a response to some change in the environment (related to adaptation) e.g.: Continuous bad smell, Darkness, monotonous speech Individual factors: - Emotional state, Motives, Pastexperience, Mental set as your expectations and aspirations affect the scope of stimuli you attend 2- Organization: It is the second part of the perception process, in which we sort and categorize information that we perceive based on innate and learned cognitive patterns. Perception organization theories 1- Gestalt theory the Gestalt concept: people perceive objects as a whole pattern and the whole is greater than the sum of its parts i.e. stimuli are usually perceived in groups or being related to one another The Gestalt principles of grouping include four types: similarity, proximity, continuity, and closure. stimulus factors: A- Proximity: perception tends to group stimuli that are close together as part of the same object, and stimuli that are far apart as two separate objects. B- Similarity: Stimuli will be perceived as being together (grouping) if they share same common character C- Closure: It refers to the mind's tendency to see complete figures or forms even if a picture is incomplete. D- Continuity: It makes sense of stimuli that overlap: when there is an intersection between two or more objects, people tend to perceive each as a single uninterrupted object 2- Perceptual Constancy law: It is the ability of perceptual systems to recognize a stable and consistent object from widely varying sensory inputs i.e. the tendency to perceive an object you are familiar with as having a constant shape, size, and brightness despite the stimuli changes that occur. 3- Perception of distance and depth: Auditory cues: 1- distance includes intensity and clarity 2- Direction Visual cues: we relay on it to correlate the third dimension 1- binocular cues 2- monocular cues Binocular cues refer to those depth cues in which both eyes are needed to perceive. There are two important binocular cues; convergence and retinal disparity. A- Convergence refers to the fact that the closer an object, the more inward our eyes need to turn in order to focus. The farther our eyes converge, the closer an object appears to be. B- Since our eyes see two images which are then sent to our brains for interpretation, the distance between these two images, or their retinal disparity, provides another cue regarding the distance of the object. Monocular cues are those cues which can be seen using only one eye. They include size; texture, overlap, shading, height, and clarity. Size refers to the fact that larger images are perceived as closer to us, especially if the two images are of the same object.  The texture of objects tend to become smoother as the object gets farther away, suggesting that more detailed textured objects are closer. The shading or shadows of objects can give a clue to their distance, allowing closer objects to cast longer shadows which will overlap objects which are farther away. 3- Interpretation: It is the key element to discover the meaning of our perception as it answers the question what does it mean Mechanism: By matching a new stimulus against generalized models that are stored in the memory e.g.: familiar events or faces generalized model is prototype or schema. Disorders of perception 1- Perceptual loss (agnosia) Visual agnosia: inability to recognize images with intact vision ▪alexia (inability to recognize written material with intact vision and previous knowledge). ▪Prospagnosia: Faces 2- Perceptual distortion: Micropsia (objects appear smaller) ▪macropsia (objects appear larger) ▪hyperacusis (sounds are louder) ▪hypoacusis (sounds are softer). 3- Perceptual deception: ▪Illusions: misinterpretation of existing stimuli, e.g. mirage, seeing a rope as a snake. ▪Hallucinations: perception in the absence of external stimuli Extrasensory perception These are phenomena where processes of information and/or energy exchange exist without explanation in terms of current science or physical mechanisms. Telepathy: thought transference from one person to another without the mediation of any known channel of sensory communication. Clairvoyance: perception of concealed objects i.e. that does not give a stimulus to the known senses. Precognition: perception of future events without any known inferential process.