Sensation and Perception

Sensation

is the process whereby stimulation of the receptor cells in the sense organs results in a neural impulse to the brain.

Perception is the brain’s interpretation of this sensory

information. The process of interpreting sensation to make

them a meaningful experience

Difference threshold

is the average of the two differences between the comparison stimuli and the standard.

Brain Areas Interpreting Sensation

Perception

is the result of stimulation; an understanding of the nature of objects, their position, shape, size, distance, smell, taste, texture and even their meaning.

It entails the organization, interpretation, elaboration, and understanding of this sensory information.

Perception - involves your reaction to incoming stimuli.

VISUAL PERCEPTUAL SYSTEMMajor Functions:

Localization – Determining where object are. In order to

locate, we first have to separate objects from one another.

Figure-Ground Organization

FIGURE AND GROUND

Gestalt Principles of Grouping

Connectedness

Common Fate

Proximity

tells us that when objects near each other they tend to be seen as a group or a unit,

Similarity tells us that when objects having similar

characteristics tend to be seen as a group. Good Continuation is when objects arranged in either a straight line or

a curve tends to be perceived as a group. Closure is that even if a figure has a gap, we tend to

perceive as a closed, complete figure.

Connectedness

is when objects are uniform and linked together, we perceive them as a single unit.

Common Fate is when objects move in the same direction,

we tend to se then as a single unit.

Depth Perception

is an understanding of how far an object is from us by converting two-dimensional information into three dimensions.

It tells us which objects are closer or farther away from us.

Perception of depth is aided by certain “depth cues.”

There are two types of depth cues: monocular or pictorial cues, and another is

binocular cues. Monocular or Pictorial Cues are

perceivable even by using only one eye.

Under monocular cues, there are also eight kinds:(1) relative size is seen among similar objects

that differ in size; we interpret smaller objects as being farther away;

(2) superposition is when an object obstructs the view of another, we perceive the overlapping object as nearer;

(3) height in field

is looking at the horizon, objects that appear higher are perceived to be farther;

(4) linear perspective is when parallel lines appear converge, they are

perceived to be vanishing in the distance;

(5) texture gradient is a gradual change from a coarse, distinct texture to

a fine indistinct texture signals increasing distance and objects far away appear smaller and more densely packed;

(6) relative clarity

is seen because light from distant objects passes through more atmospheres, we can perceive hazy objects as farther away than sharp, clear objects;

(7) light and shadow is when nearby objects reflect light to our

eyes, thus, given two identical objects, the dimmer one seems farther away, and shading, too, produces a sense of depth consistent with the assumed light source;

(8) motion parallax

is when traveling, nearer objects seem to move quicker as compared to farther objects.

Relative Size

Superposition

Height in Field Linear Perspective

Assignment: Perception

Using your camera/digital phone, capture 5 examples showing 5 out of the 8 different monocular cues, then have it developed or printed in wallet sizes (2R). Paste it in the space provided then write below each picture when and where the picture was taken. Create a title for each picture just like the pictures seen in a photo gallery/exhibit. (Feb. 4 – submission)

Title: ____________________________ Place Taken: ______________________ Date Taken: ______________________ Type of Monocular Cue: ____________ Brief Explanation: _________________ _________________________________________

__________________________________________________________________________________________________________

B. Auditory perception Sound localization or perception of sound

direction is dependent on the properties of the sound source and separation of the two ears.

Binaural clues 1. Time difference – sound waves arriving at

one side of the ear is detected as coming from that direction.

2. Intensity difference – sounds are more intense in one direction as perceived as coming from that direction.

3. Phase difference – pressure of the sound wave at any part ,place or movement. People move their heads to try to judge direction of sound.

4. Learning experiences - we turn towards the sound familiar to us.

5. Echoes and distortion in an enclosed place familiar to us.

C. Tactual perception Local signs or (signs of location) allow us to make

appropriate responses to corresponding stimuli. Local signs arise through learning.

D. Olfactory and Gustatory perception Pressure, temperature, pain altogether produce the taste

in a food / drink . We commonly confuse taste when it is smell that works to identify it.

Note: Sensitivity of the taste varies according to point of application and temperature of the substances.

Errors of perception 1. Illusion – impression from experience which does not

correctly represent the objective situation outside the observer. It may be used to denote error in immediate perception and in meaning.

2. Hallucination – impressions of sensory vividness arising from inner , mental factor.

Alucinatio – latin term ( to dream, to talk idly, to wander

mentally). E.g. Schizophrenics and manic depressives (constrcuct a fantasy

world to suit his own emotional conflict with reality).

3. Delusion – false belief organized from both perception and memory. An individual may mistake his own identity or misinterpret the actions of others.

Extra sensory perception Perception without the mediation of the senses. 1. Telepathy – thought transmission from one mind to

another. 2. Clairvoyance – extrasensory awareness of objects. 3. Precognition – foreknowledge of specific events

without any rational means. 4. Psychokinesis – mind over matter – mental operations

that influences a material body or an energy system.

Assignment: CONSCIOUNESS AND ITS ALTERED STATES

Try to remember one of your most vivid/significant dreams then write a short story about it like who are the people in your dream and what it is about. Search several books or the internet and write its interpretation in the activity sheet given. Also write the source of where you got the interpretation of your dreams.

Your Dream Interpretation - Source

Consciousness

A stream of ever changing flow of awareness. It is a state or the quality of being aware of internal thought processes or of external objects, states or facts.

Two Divisions of Consciousness:Waking State of Consciousness – 1. includes a mixture of sensations from the outside

world, sensations from the body, memories of the past, thoughts, feelings, perceptions and images, and expectations about the future that occur when we are awake and reasonably alert. However, it may be selective of the stimuli that are attended to.

2. Altered State of Consciousness (ACS) – A radical deviation from the overall pattern of functioning of the mind during ordinary waking state of consciousness such that a new, overall pattern is superimposed on one’s experience.

Kinds of Altered States of ConsciousnessSleep Sleep consists of five stages that involve

different levels of awareness, consciousness, and responsiveness.

Stages of Sleep [as suggested by the quality of brainwaves displayed by an apparatus

called, electroencephalograph (EEG)]

Sleep Disorders

Insomnia – characterized by difficulty in falling asleep,

frequent nighttime awakenings, waking too early, or any combination of these

Narcolepsy – an uncontrollable tendency to fall asleep,

usually lasting for less than five minutes

Sleep Apnea –

breathing difficulty or even cessation of breathing while the person is asleep. Breathing may stop from 20 seconds to 2 minutes. The sleeper has to wake up several times throughout the night to gulp for air, but may not be aware of it.

Night Terrors – the person might sit up or walk around, talk

incoherently, experience a doubling of heart and breathing rates, and appear terrified. The night-terror sufferer seldom wakes up fully during the episode and recalls little or nothing the next morning – at most, a fleeting, frightening

Sleepwalking (somniloquy) and Sleep talking (somnambulism) – these are more common in children than

adults. Children generally have no memory of such events, usually do not require treatment, and usually outgrow the disorder

Sleepwalking (somniloquy) and Sleep talking (somnambulism) –

these are more common in children than adults. Children generally have no memory of such events, usually do not require treatment, and usually outgrow the disorder