![]() Moreover, the requirement of auditory cortex, in particular task settings, points toward two alternative mechanistic implications. Thus, auditory cortex does not seem to be always necessary for sound discrimination. ![]() Indeed, lesions or reversible silencing of auditory cortex lead to deficits or have little effect, depending on task conditions, silencing methods, and animal models ( Diamond and Neff, 1957, Gimenez et al., 2015, Harrington et al., 2001, Jaramillo and Zador, 2011, Kuchibhotla et al., 2017, Ohl et al., 1999, Pai et al., 2011, Rybalko et al., 2006, Talwar et al., 2001). This apparent contradiction is particularly evident in hearing, for which involvement of auditory cortex (AC) is controversial even for discrimination of two distinct sounds. In addition, cortical stimulation experiments show that primary cortex for all sensory modalities can perturb perceptual decisions or initiate sensory-driven behaviors ( Choi et al., 2011, Houweling and Brecht, 2008, Huber et al., 2008, Musall et al., 2014, O’Connor et al., 2013, Peng et al., 2015, Salzman et al., 1990, Yang et al., 2008, Znamenskiy and Zador, 2013), suggesting a role in perception. However, several studies also report sensory-based behaviors that are abolished or severely impaired by primary sensory cortex silencing ( Letzkus et al., 2011, O’Connor et al., 2010, Poort et al., 2015, Sachidhanandam et al., 2013). In animals, classical associative conditioning ( Lashley, 1950, LeDoux et al., 1984) or some operant behaviors ( Hong et al., 2018) based on sensory stimuli can be performed in the absence of primary sensory cortex. For example, human subjects with primary visual cortex lesions display residual visual abilities, a phenomenon termed “blindsight” ( Sanders et al., 1974, Schmid et al., 2010). Primary sensory areas are often viewed as necessary links between peripheral sensory information and decision centers, but multiple observations challenge this simplified model. The above requires a different kind of focus, on the students' part, from that of simply repeating minimal pairs or triads it can be very revealing as to what sounds are being confused.The role of primary sensory cortical areas in perceptual decisions is complex. If students' listening skills are good, the above could be expanded to minimally different sentences ("He bought a peck of tomatoes" / "He bought a pack of tomatoes") use the same "S" / "D" technique. ("pet / pat / pet: D-2 bait / bait / bet: D-2 mat / mat / mat: S") If you've dictated triads and the group was "D," you can also ask students to mark how many different (i. ("peak / pick seek / seek stick / stick lick / leak") Ask students to mark S or D (for "same" and "different") to describe what they have heard. Vary what you dictate-sometimes using two or three different words, sometimes dictating the same word two or three times. Dictate at least five pairs / triads, each focusing on the same sounds. Dictate pairs or triads of minimally different words (e.g., "seat / sit" or "sit / set / sat," "tag / tack."). For a quick (but telling) exercise in aural discrimination of often-confused sounds,
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