Biological Bases of Behavior: Sensation

Touch

  • Touch promotes well-being and is a tactile sense needed from birth.

  • Skin is the largest sense receptor, containing cells for pressure, warmth, cold, and pain.

  • Other sensations like tickling, hot, and itching are combinations of these basic touches.

  • Cognition affects the interpretation of touch sensations.

Pain

  • Gate-control theory: Spinal cord contains a neurological "gate" blocking or allowing pain signals to the brain.

  • Small nerve fibers open the gate, while large fibers can block pain signals.

  • Pain is a biopsychosocial phenomenon, adaptive for detecting harm.

  • Nociceptors: Sensory receptors detect harmful stimuli (temperature, pressure, chemicals).

  • Endorphins: Natural painkillers that reduce pain responsiveness.

  • Psychological factors: Motivation and distraction can influence pain perception.

  • Social-cultural factors: Cultural norms and empathy affect pain experience.

  • Pain treatment: Includes medicines, surgeries, and therapies like hypnosis and placebos.

  • Placebos and distractions: Can reduce pain by influencing beliefs and cognitive focus.

  • Congenital Insensitivity to Pain (CIP): A rare genetic disorder causing inability to feel physical pain.

Taste (Gustation)

  • Five basic tastes: sweet, salty, sour, bitter, umami.

  • Taste buds: Receptors on tongue and in mouth process chemicals.

  • Psychological factors: Expectations and framing influence taste perception.

Smell (Olfaction)

  • Smell bypasses the thalamus directly to the olfactory bulb.

  • Olfactory receptors: Detect numerous smells through combinatorial activation.

  • Smell and memory: Strong connection, evoking emotional memories.

  • Anosmia: Inability to smell.

Body Position and Movement

  • Kinesthesis: Sense of body part position and movement.

  • Vestibular sense: Sense of balance and body position.

  • Proprioceptors: Position and motion sensors in muscles, joints, and tendons.

  • Semicircular canals and vestibular sacs: Fluid-filled structures in the inner ear that monitor balance.

Sensory Interaction and Embodied Cognition

  • Sensory interaction: One sense influencing another (e.g., smell influencing taste).

  • Embodied cognition: Influence of bodily sensations on cognitive preferences and judgments.

  • Examples: Smell and taste create flavors; vision and vestibular sense aid kinesthesis; McGurk effect (visual input altering auditory perception).

  • Sensation and perception work together; embodied cognition links sensations to cognition.