A Cortical Network for the Encoding of Object Change

Abstract

Understanding events often requires recognizing unique stimuli as alternative, mutually exclusive states of the same persisting object. Using fMRI, we examined the neural mechanisms underlying the representation of object states and object-state changes. We found that subjective ratings of visual dissimilarity between a depicted object and an unseen alternative state of that object predicted the corresponding multivoxel pattern dissimilarity in early visual cortex during an imagery task, while late visual cortex patterns tracked dissimilarity among distinct objects. Early visual cortex pattern dissimilarity for object states in turn predicted the level of activation in an area of left posterior ventrolateral prefrontal cortex (pVLPFC) most responsive to conflict in a separate Stroop color-word interference task, and an area of left ventral posterior parietal cortex (vPPC) implicated in the relational binding of semantic features. We suggest that when visualizing object states, representational content instantiated across early and late visual cortex is modulated by processes in left pVLPFC and left vPPC that support selection and binding, and ultimately event comprehension.

Tracking competition and cognitive control during language comprehension with multi-voxel pattern analysis

“…This result is compatible with a handful of other studies that have reported a relationship between left VLPFC activity and dissimilarity between MVPs evoked by competing stimuli elsewhere in the brain. In a recent study by Hindy and colleagues (2015), in early visual cortex, the neural dissimilarity between MVPs evoked by two incompatible states of the same object (e.g., a cracked versus intact egg) was predicted by increased left VLPFC response during the presentation of the object in its second state.…”

“…Hindy et al, 2012; Hindy et al, 2015). On each trial, subjects were presented with a single word and were instructed to press one of three response buttons that corresponded to the typeface color (i.e., blue, yellow, or green).…”

“…In the episodic memory domain, researchers have used this technique to quantify competition during targeted memory retrieval, where the same cue simultaneously elicits two associated memories, although one of the associates is task-irrelevant (e.g., Kuhl et al, 2012; Wimber et al, 2015). Similarly, in a study of event comprehension, Hindy and colleagues (2015) examined whether MVPs reflected the co-activation of two mutually exclusive states of the same object.…”

Semantic variability predicts neural variability of object concepts

“…Typically, semantic effects in early visual cortex are reported under conditions of explicit mental imagery (e.g., Hindy et al, 2013; Lee et al, 2012). However, additional work has found that early visual areas are recruited even when subjects are not instructed to imagine objects.…”

Reworking the language network

“…; Box 2) – relies on functionally specialized vs. domain-general cognitive and neural machinery has been long debated. One important take-away message from the preceding section is that under many definitions, the language network includes both relatively functionally specialized brain regions [24,28–30] and brain regions better thought of as part of a domain-general cognitive control network [31–35] (for a review see [36]). But, our opening question, and a central concern for the field, is whether language requires specific computations, not to characterize any particular brain region.…”