Frequency selectivity measured both psychophysically and physiologically

摘要: The ability to resolve the individual frequency components of a complex sound is known as selectivity. auditory system seems act series overlapping band-pass filters or (AF), width which describe It fundamental and extensively studied property system, yet its neural basis not fully understood. This due, in part, fact that two distinct approaches are taken explore it; psychophysics physiology, results difficult reconcile. AF measured quite different ways sub-fields. Psychophysics measures whole by using masking paradigms measure bandwidth from behavioural data. A preferred method human notched noise (NN) forward with fixed signal level, since it does suffer confounds like suppression off-frequency listening. In physiology can be for single cells, population at various levels traditionally done observing number action potentials elicited response pure tone stimuli. highly non-linear so comparing such vastly problematic. Also, detection threshold 'signal' sounds; how this compares mean spike rates used clear. Attempts have been made past apply same animals both psychophysical physiological bandwidths, varying degree success. No successful attempt has use an up-to-date psychophysics. thesis I take step towards 1) developing novel allows masked NN bandwidths behaviourally ferret, 2) applying paradigm measuring guinea pig inferior colliculus (IC) primary cortex (A1) neurons. addition theory (SDT) approach on data make more comparable ones. Results show successfully simultaneously animal, these measurements close agreement one another previous methods. Results study IC neurons narrower than estimates bandwidth, However, peripheral perceptual finding differs substantially studies. Unexpectedly, however, estimated A1 much finer tuning high frequencies seen further down system. only neurons, but also psychophysically estimates, represent whole. may related greater non-linearity cortical compared those midbrain lower. This work demonstrates possible reconcile appropriate highlights nature care must when selectivity approaches. provides physiologically allowing direct comparison between two; vital investigating