Sensory system tuning (filtering) and organization

Sensory system tuning (filtering) and organization • All sensory systems are designed to extract information from the environment • Sensory systems are usually selective • Systems tend to focus on a range of what is available • Range tends to be restricted to what is “biologically meaningful” • Range is thus “tuned” based on the specificity of the ecological demands • Tuning tends to have an “optimum” or “best” stimulus • Deviation from this “best” yields less than optimal sensitivity • Keep track of the origin of the tuning curve: it is behavioral or neural data. Katydid killer auditory tuning Parasitoid fly auditory tuning

Optimum sensitivity does not necessarily mean “most meaningful” Vision Olfaction

Moth olfactory tuning: Concentration response function (receptor neurons) for different odors

Moth olfactory tuning concentration response function (output)

Moth olfactory tuning: Concentration response function (behavioral)

Increased sensitivity usually means increased neural representation in sensory array Vision

Increased sensitivity usually means increased neural representation in sensory array Olfaction

Increased sensitivity usually means increased neural representation centrally Moth olfactory tuning Male antennal lobe Female antennal lobe

Increased sensitivity usually means increased neural representation centrally Relative volume of somatosensory cortex devoted to area of skin

Central organization Somatotopic integrity: maintains an organized representation

Retinotopic integrity of sensory input at the level of primary visual cortex

Chemotopic integrity: maintains an organized representation of receptor type

Types of sensory systems found in nature • Chemical senses • Olfaction • Taste • Vision • Auditory • Vestibular • Somatosensory • Proprioception • Nociception • Mechanosensation • Thermosensation • Magnosensation • Electromagnosensation • Geomagnosensation • Geosensation

Sensory system tuning (filtering) and organization