Development and Plasticity of Intra- and Intersensory Information Processing

Abstract

The functional architecture of sensory brain regions reflects an ingenious biological solution to the competing demands of a continually changing sensory environment. While they are malleable, they have the constancy necessary to support a stable sensory percept. How does the functional organization of sensory brain regions contend with these antithetical demands? Here we describe the functional organization of auditory and multisensory (i.e., auditory-visual) information processing in three sensory brain structures: (1) a low-level unisensory cortical region, the primary auditory cortex (A1); (2) a higher-order multisensory cortical region, the anterior ectosylvian sulcus (AES); and (3) a multisensory subcortical structure, the superior colliculus (SC), We then present a body of work that characterizes the ontogenic expression of experience-dependent influences on the operations performed by the functional circuits contained within these regions. We will present data to support the hypothesis that the competing demands for plasticity and stability are addressed through a developmental transition in operational properties of functional circuits from an initially labile mode in the early stages of postnatal development to a more stable mode in the mature brain that retains the capacity for plasticity under specific experiential conditions. Finally, we discuss parallels between the central tenets of functional organization and plasticity of sensory brain structures drawn from animal studies and a growing literature on human brain plasticity and the potential applicability of these principles to the audiology clinic.

Interactions between space and effectiveness in human multisensory performance

“…Changing the location of a multisensory stimulus, which often includes a change in distance from the observer, often leads to changes in effective intensity and its temporal structure. Multisensory integration is established early in life (Bremner, Lewkowicz, & Spence, 2012; Lewkowicz & Ghazanfar, 2009; Massaro, 1984; Massaro, Thompson, Barron, & Laren, 1986; Neil, Chee-Ruiter, Scheier, Lewkowicz, & Shimojo, 2006; Wallace, Carriere, Perrault, Vaughan, & Stein, 2006; Wallace & Stein, 1997) and is highly susceptible to the statistics of our perceptual environment (Baier, et al, 2006; den Ouden, et al, 2009; McIntosh & Gonzalez-Lima, 1998) throughout development (Carriere, et al, 2007; Polley, et al, 2008; Wallace, Perrault, Hairston, & Stein, 2004; Wallace & Stein, 2007) and even in adulthood (A. R. Powers, 3rd, Hevey, & Wallace, 2012; A.…”

“…In an effort to “decide” what should be integrated (and what should not be integrated), the brain capitalizes on the statistical regularities of cues from the different senses that provide important information as to the probability that they are related (Alais & Burr, 2004; Altieri, Stevenson, Wallace, & Wenger, 2015; Baier, Kleinschmidt, & Muller, 2006; den Ouden, Friston, Daw, McIntosh, & Stephan, 2009; Massaro, 1984; McIntosh & Gonzalez-Lima, 1998; Polley, et al, 2008; Shinn-Cunningham, 2008; Wallace & Stein, 2007). Thus, multisensory integration (and its resultant behavioral and perceptual benefits) is in part determined by physical factors associated with the stimuli to be paired.…”

Auditory map plasticity: diversity in causes and consequences

“…These observations prompted a reconceptualization of developmental and adult plasticity as more accurately representing successive epochs of exposure-based and reinforcement-based plasticity, respectively [95, 96]. However, as the exception that ultimately proves the rule, Eggermont and colleagues have shown a surprising and profound tonotopic reorganization in adult cats passively exposed to moderate intensity acoustic stimuli that aggregate spectral energy into a restricted frequency band [97–102].…”

The construct of the multisensory temporal binding window and its dysregulation in developmental disabilities

“…Animal model studies have shown that multisensory neurons and their associated integrative properties mature over a protracted period of developmental life that extends well into “adolescence” [61, 164-167]. In addition, these studies have shown remarkable plasticity in the development of these processes, such that changes in the statistical structure (i.e., spatial and temporal stimulus relations) of the early sensory world result in the development of integrative properties that match these statistics [53, 168-170]. …”