The Role of Top-Down Task Context in Learning to Perceive Objects

Abstract

In high-level perceptual regions of the ventral visual pathway in humans, experience shapes the functional properties of the cortex: the fusiform face area responds most strongly to faces of familiar rather than unfamiliar races, and the visual word form area (VWFA) is tuned only to familiar orthographies. But are these regions affected only by the bottom-up stimulus information they receive during learning, or does the effect of perceptual experience depend on the way that stimulus information is used during learning? Here, we test the hypothesis that top-down influences (i.e., task context) modulate the effect of perceptual experience on functional selectivities of the high-level visual cortex. Specifically, we test whether experience with novel visual stimuli produces a greater effect on the VWFA when those stimuli are associated with meanings (via association learning) but produces a greater effect on shape-processing regions when trained in a discrimination task without associated meanings. Our result supports this hypothesis and further shows that learning is transferred to novel objects that share parts with the trained objects. Thus, the effects of experience on selectivities of the high-level visual cortex depend on the task context in which that experience occurs and the perceptual processing strategy by which objects are encoded during learning.

Task by stimulus interactions in brain responses during Chinese character processing

“…The analyses further revealed interactions between task and stimulus type throughout this network, suggesting that its function is not fixed, but can be reorganized in response to task demands (Starrfelt & Gerlach, 2007; Song, Hu, Li, Li, & Liu, 2010; Xue et al, 2010; Wang et al, 2011). The form of this interaction was remarkably similar throughout fusiform, middle and inferior frontal gyri, such that activity was overall quite low, and not influenced by stimulus class in the symbol detection task, but strongly affected by stimulus class in the lexical decision task.…”

Quantifying interindividual variability and asymmetry of face-selective regions: A probabilistic functional atlas

“…Third, the large interindividual functional variability may arise from the functional plasticity of the brain through cortical competition. Previous studies on visual development (Golarai et al, 2007), expertise (Gauthier et al, 2003), and plasticity in sensory maps (Polley et al, 2006;Song et al, 2010) have revealed a displacement of map boundaries due to cortical competition. Thus, individual experiences in the early or even late years of development may significantly contribute to the interindividual variability of the FSRs.…”

Pretraining Cortical Thickness Predicts Subsequent Perceptual Learning Rate in a Visual Search Task

“…It is usually characterized by some degree of specificity to the trained stimulus attributes including stimulus location (e.g., Ball and Sekuler 1982;Karni and Sagi 1991;Poggio et al 1992;Ahissar et al 1998;Saffell and Matthews 2003;Jastorff et al 2006;Bi et al 2010), the recruitment of stimulus-specific cortical areas (e.g., Vaina et al 1998;Schwartz et al 2002;Furmanski et al 2004;Grossman et al 2004;Song et al 2010;Bi et al 2014;Frank et al 2014), as well as stability of acquired behavioral improvements over time (e.g., Ball and Sekuler 1987;Karni and Sagi 1993;Watanabe et al 2002;Bi et al 2014;Frank et al 2014). The study of perceptual learning has the potential to provide insights into neural correlates of learning more generally.…”

“…However, to confirm this a posteriori, we measured brain activity during performance of the learning task, relative to a control condition, for the first and last training sessions using functional MRI (fMRI). We predicted increased activity in the 4 regions of interest (ROIs) after behavioral training (see Vaina et al 1998;Schwartz et al 2002;Furmanski et al 2004;Grossman et al 2004;Kourtzi et al 2005;Yotsumoto et al 2008;Song et al 2010;Frank et al 2014).…”