Abstract goal representation in visual search by neurons in the human pre-supplementary motor area

Abstract The medial frontal cortex is important for goal-directed behaviours such as visual search. The pre-supplementary motor area (pre-SMA) plays a critical role in linking higher-level goals to actions, but little is known about the responses of individual cells in this area in humans. Pre-SMA dysfunction is thought to be a critical factor in the cognitive deficits that are observed in diseases such as Parkinson’s disease and schizophrenia, making it important to develop a better mechanistic understanding of the pre-SMA’s role in cognition. We simultaneously recorded single neurons in the human pre-SMA and eye movements while subjects performed goal-directed visual search tasks. We characterized two groups of neurons in the pre-SMA. First, 40% of neurons changed their firing rate whenever a fixation landed on the search target. These neurons responded to targets in an abstract manner across several conditions and tasks. Responses were invariant to motor output (i.e. button press or not), and to different ways of defining the search target (by instruction or pop-out). Second, ∼50% of neurons changed their response as a function of fixation order. Together, our results show that human pre-SMA neurons carry abstract signals during visual search that indicate whether a goal was reached in an action- and cue-independent manner. This suggests that the pre-SMA contributes to goal-directed behaviour by flexibly signalling goal detection and time elapsed since start of the search, and this process occurs regardless of task. These observations provide insights into how pre-SMA dysfunction might impact cognitive function.

Download Full-text

Distinct neuronal organizations of the caudal cingulate motor area and supplementary motor area in monkeys for ipsilateral and contralateral hand movements

Journal of Neurophysiology ◽

10.1152/jn.00854.2014 ◽

2015 ◽

Vol 113 (7) ◽

pp. 2845-2858 ◽

Cited By ~ 5

Author(s):

Yoshihisa Nakayama ◽

Osamu Yokoyama ◽

Eiji Hoshi

Keyword(s):

Neuronal Activity ◽

Supplementary Motor Area ◽

Functional Organization ◽

Hand Movement ◽

Motor Area ◽

Hand Movements ◽

Button Press ◽

Cingulate Motor Area ◽

Contralateral Hand ◽

Hand Preferences

The caudal cingulate motor area (CMAc) and the supplementary motor area (SMA) play important roles in movement execution. The present study aimed to characterize the functional organization of these regions during movement by investigating laterality representations in the CMAc and SMA of monkeys via an examination of neuronal activity during a button press movement with either the right or left hand. Three types of movement-related neuronal activity were observed: 1) with only the contralateral hand, 2) with only the ipsilateral hand, and 3) with either hand. Neurons in the CMAc represented contralateral and ipsilateral hand movements to the same degree, whereas neuronal representations in the SMA were biased toward contralateral hand movement. Furthermore, recording neuronal activities using a linear-array multicontact electrode with 24 contacts spaced 150 μm apart allowed us to analyze the spatial distribution of neurons exhibiting particular hand preferences at the submillimeter scale. The CMAc and SMA displayed distinct microarchitectural organizations. The contralateral, ipsilateral, and bilateral CMAc neurons were distributed homogeneously, whereas SMA neurons exhibiting identical hand preferences tended to cluster. These findings indicate that the CMAc, which is functionally organized in a less structured manner than the SMA is, controls contralateral and ipsilateral hand movements in a counterbalanced fashion, whereas the SMA, which is more structured, preferentially controls contralateral hand movements.

Download Full-text

The performance costs of interruption during visual search are determined by the type of search task

Cognitive Research Principles and Implications ◽

10.1186/s41235-021-00322-0 ◽

2021 ◽

Vol 6 (1) ◽

Author(s):

David Alonso ◽

Mark Lavelle ◽

Trafton Drew

Keyword(s):

Working Memory ◽

Visual Search ◽

Cognitive Processes ◽

Search Task ◽

Critical Role ◽

Primary Task ◽

Task Duration ◽

Search Tasks ◽

Interruption Costs ◽

The Cost

AbstractPrior research has shown that interruptions lead to a variety of performance costs. However, these costs are heterogenous and poorly understood. Under some circumstances, interruptions lead to large decreases in accuracy on the primary task, whereas in others task duration increases, but task accuracy is unaffected. Presently, the underlying cause of these costs is unclear. The Memory for Goals model suggests that interruptions interfere with the ability to represent the current goal of the primary task. Here, we test the idea that working memory (WM) may play a critical role in representing the current goal and thus may underlie the observed costs associated with interruption. In two experiments, we utilized laboratory-based visual search tasks, which differed in their WM demands, in order to assess how this difference influenced the observed interruption costs. Interruptions led to more severe performance costs when the target of the search changed on each trial. When the search target was consistent across trials, the cost of interruption was greatly reduced. This suggests that the WM demands associated with the primary task play an important role in determining the performance costs of interruption. Our findings suggest that it is important for research to consider the cognitive processes a task engages in order to predict the nature of the adverse effects of interruption in applied settings such as radiology.

Download Full-text