Sustained neural activity during the delay phase of spatial working memory tasks is compelling evidence for the neural correlate of active storage and maintenance of spatial information, however, it does not provide insight into specific mechanisms of spatial coding. This activity may reflect a range of processes, such as maintenance of a stimulus position or a prepared motor response plan. The aim of our study was to examine neural evidence for the use of different coding strategies, depending on the characteristics (...) and demands of a spatial working memory task. Thirty-one and 44 participants performed a spatial working memory task while we measured their brain activity using fMRI in two separate experiments. Participants were asked to remember the position of a briefly presented target stimulus and, after a delay period, to use a joystick to indicate either the position of the remembered target or an indicated non-matching location. The task was designed so that the predictability of the response could be manipulated independently of task difficulty and memory retrieval process. We were particularly interested in contrasting conditions in which participants could use prospective coding of the motor response or had to rely on retrospective sensory information. Prospective motor coding was associated with activity in somatomotor, premotor, and motor cortices and increased integration of brain activity with and within the somatomotor network. In contrast, retrospective sensory coding was associated with increased activity in parietal regions and increased functional connectivity with and within secondary visual and dorsal attentional networks. The observed differences in activation levels, dynamics of differences over trial duration, and integration of information within and between brain networks provide compelling evidence for the use of complementary spatial working memory strategies optimized to meet task demands. (shrink)

Mechanisms of selective attention are vital for coherent perception and action. Recent advances in cognitive neuroscience have yielded key insights into the relationship between neural mechanisms of attention and eye movements, and the role of frontal and parietal brain regions as sources of attentional control. Here we explore the growing contribution of reversible neurodisruption techniques, including transcranial magnetic stimulation and microelectrode stimulation, to the cognitive neuroscience of spatial attention. These approaches permit unique causal inferences concerning the relationship between neural processes (...) and behaviour, and have revealed fundamental mechanisms of attention in the human and animal brain. We conclude by suggesting that further advances in the neuroscience of attention will be facilitated by the combination of neurodisruption techniques with established neuroimaging methods. (shrink)

The absence of a common understanding of attention plagues current research on the topic. Combining the findings from three domains of research on attention, this paper presents a univocal account that fits normal use of the term as well as its many associated phenomena: attention is a process of mental selection that is within the control of the subject. The role of the subject is often excluded from naturalized accounts, but this paper will be an exception to that rule. The (...) paper aims to show how we might reinstate the subject into the act of attention, endorsing the ordinary notion that attention is a direction of the mind by the subject, rather than a mere occurrence or happening. To do so, it lays out the best work of phenomenology, psychology, and neuroscience on specifying the nature of attention and, in finding them individually wanting, combines them into a unified view that avoids the problems of each. (shrink)