Psych 101 Exam 2 study guides

Sensation

Process by which our sensory receptors detect physical energy (stimulus) from the environment and convert it into neural signals.

Perception

Process by which our brains organize and interpret our sensations, enabling us to recognize objects and events as meaningful.

Difference between sensation and perception

Sensation is input about the physical world obtained by sensory receptors, while perception is the brain's process of selecting, organizing, and interpreting these sensations.

Sensory receptors

Detect only the energy that they are capable of sensing; not all environmental energy is detected.

Absolute threshold

Minimum stimulation needed to detect a particular stimulus; stimuli must be above this threshold to be detected.

Signal detection theory

Predicts how and when we detect the presence of a faint stimulus amid background stimulation, influenced by psychological states.

Difference threshold (just noticeable difference)

Minimal change in a stimulus that can just barely be detected.

Sensory adaptation

Diminishing sensitivity to an unchanging stimulus, allowing focus on informative changes.

Visual processing

Involves detection of light energy by photoreceptors in the eye.

Photoreceptors

Special receptors in the eye that detect light energy; includes rods (no color) and cones (color).

Fovea

Central point in the retina where the eye’s cones cluster.

Optic nerve

Carries neural impulses from the eye to the brain, connecting to the thalamus and visual cortex.

Blind spot

Area where the optic nerve leaves the eye, lacking receptor cells.

Feature detection neurons

Located in the temporal lobe, respond to complex information like faces or movement.

Prosopagnosia

Neurological condition characterized by the inability to recognize familiar faces.

Bottom-up processing

Starts with sensory receptors and is based on incoming data without preconceived ideas.

Top-down processing

Influenced by previous experiences, expectations, beliefs, and memories affecting perceptions.

Neuroplasticity

The brain’s ability to change and reorganize itself over time.

Structural plasticity

Changes in the number of neurons and connections between them.

Synaptic plasticity

Strengthening or weakening of synapses based on communication between neurons.

Circadian rhythms

Endogenous rhythms that regulate biological processes, including sleep/wake cycles.

Suprachiasmatic nucleus (SCN)

The brain's biological clock located in the hypothalamus, regulating circadian rhythms.

Retinohypothalamic pathway

Pathway that signals the SCN about light availability, affecting sleep timing.

Sleep pressure

Desire to sleep, correlated with adenosine levels in the brain.

Electroencephalogram (EEG)

Test that detects electrical activity in the brain, showing brain activity during sleep.

Non-REM Sleep

Consists of four stages characterized by synchronized brain activity and no vivid dreams.

REM Sleep

One stage with desynchronized brain activity, vivid dreams, and muscle atonia.

Atonia

Complete muscle inactivity during REM sleep, allowing for eye movement without body movement.

Chronotypes

Individual differences in alertness and activity levels throughout the day.

Classical conditioning

Learning process where an organism makes connections between stimuli or events that occur together.