Introductory Cognitive and Behavioural Neuroscience: Lecture 8 (Hearing and Somatosensory Processing)

Vocabulary-style flashcards covering auditory processing, somatosensory systems, neural pathways, and cross-modal object recognition from PSYC 215 Lecture 8.

Hertz ($Hz$)

A unit of measurement for sound frequency or pitch, where higher frequencies correspond to higher pitches.

Loudness

The degree to which compressions and expansions of air differ from each other, produced by the vigor of an object's vibrations.

Timbre

The quality of sound determined by its complexity or the mix of several frequencies, providing information about the nature of the sound.

Rarefaction wave

A region of negative pressure in a longitudinal sound wave where air molecules are farther apart.

$$20\,\mu Pa$$

The amplitude of the weakest sound a healthy human ear can detect, equivalent to $20$ millionths of a Pascal.

The Outer Ear (OE)

The part of the ear consisting of the pinna, which funnels sound into the ear canal and assists with sound localization.

The Middle Ear (ME)

An air-filled cavity that serves to amplify incoming sounds.

The Inner Ear (IE)

A fluid-filled structure that transfers sound vibrations into action potentials (APs) traveling along the 8th cranial nerve.

Cilia

Fine, hair-like projections of inner and outer auditory hair cells that facilitate transduction through movement.

Tip link

A structure connecting cilia that opens ion channels when moved toward the tallest cilium, allowing an influx of $K^+$ and $Ca^{2+}$ ions.

Tonotopic Mapping

The preservation of the frequency map from the basilar membrane through subcortical structures into the primary auditory cortex ($A1$).

Inferior colliculus

A part of the auditory neural pathway that processes auditory signals and helps direct attention to unexpected sounds.

Superior colliculus

A structure that processes visual signals related to eye movements and the tracking of moving visual objects.

Coincidence detector

A neuron that responds only if it receives signals simultaneously from synapses belonging to both sets of axons from the two ears.

Cutaneous Senses

A type of somatosense that provides information from the surface of the body via skin receptors.

Proprioception

The somatosense that provides information regarding the location of the body in space.

Kinesthesia

The somatosense providing information about body movement through space, activated by stretch and limb movements.

Nociceptors

Skin receptors specialized for detecting pain stimulated by intense pressure, heat, and chemical irritants.

Mechanoreceptors

Receptors activated by vibration that transduce signals by opening ion channels to change membrane potential.

Lateral occipital complex (LOtv)

A subregion that encodes a supramodal shape representation, allowing for object identity recognition regardless of the sensory modality (vision or touch).

Optic ataxia

A clinical dissociation resulting from dorsal/parietal damage where object recognition remains intact but grasp scaling is impaired.