Miller Lab – Page 27 – The Miller Lab @ MIT

21

Jan 2015

New paper – Working Memory Capacity: Limits on the Bandwidth of Cognition

Miller Lab

In The News, Miller Laboratory

Miller, E.K. and Buschman, T.J. (2015) Working memory capacity: Limits on the bandwidth of cognition. Daedalus, Vol. 144, No. 1, Pages 112-122. View PDF

Why can your brain store a lifetime of experiences but process only a few thoughts at once? In this article we discuss “cognitive capacity” (the number of items that can be held “in mind” simultaneously) and suggest that the limit is inherent to processing based on oscillatory brain rhythms, or “brain waves,” which may regulate neural communication. Neurons that “hum” together temporarily “wire” together, allowing the brain to form and re-form networks on the fly, which may explain a hallmark of intelligence and cognition: mental flexibility. But this comes at a cost; only a small number of thoughts can fit into each wave. This explains why you should never talk on a mobile phone when driving.
20

Jan 2015

Radio New Zealand: Earl Miller interviewed about multi-tasking and technology

Miller Lab

In The News, Miller Laboratory

Radio New Zealand: Interview with Professor Earl Miller about Multi-tasking and technology

Originally aired on Afternoons, Tuesday 20 January 2015

Getting back into work routines, after a holiday break, is something many of us will already have come to grips with in recent weeks. And these routines seem to get busier all the time, as modern technology allows us to perform more and more tasks ourselves, quickly, on our tablets and smart phones. But at what cost? MIT neuroscientist Professor Earl Miller is an expert on divided attention. He argues our addiction to technology is actually making us less efficient.
5

Jan 2015

Interareal oscillatory synchronization in top-down neocortical processing

Miller Lab

Neuroscience

Bressler and Richter review evidence that top-down processing in the cortex depends on synchronization of oscillatory rhythms between brain areas. More specifically, they hypothesize that beta band (13-30 Hz) synchrony conveys information about behavioral context (task information) to neurons in sensory cortex.
5

Jan 2015

Photo of recipients of 2014 Bose Research Awards

Miller Lab

In The News, Miller Laboratory

(Back row, left to right) Vanu Bose, ’87, SM ’94, PhD ’99, son of Amar Bose; Earl Miller, the Picower Professor of Neuroscience; Jeff Grossman, an associate professor of materials science and engineering; Janet Conrad, a professor of physics; Alan Oppenheim, the Ford Professor of Engineering; and President L. Rafael Reif; and (front row, left to right) Joel Voldman, a professor of electrical engineering and computer science; Gabriel Bousquet, a PhD student in mechanical engineering; and Nicola Ferralis, a research scientist for materials science and engineering.

Bose grants reward risk. Five innovative, high-risk projects launch with support from Prof. Amar G. Bose Research Grants.
16

Dec 2014

Frontoparietal networks involved in categorization and item working memory

Miller Lab

Neuroscience

Braunlich et al compared stimulus identity vs categorization tasks using fMRI in humans. They applied a Constrained Principal Components Analysis. They found evidence for two distinct frontoparietal networks. One that rapidly analyzes the stimuli and a second one that more slowly categorizes them.
16

Dec 2014

Attentional Filtering of Visual Information by Neuronal Ensembles in the Primate Lateral Prefrontal Cortex

Miller Lab

Neuroscience

Virtually all studies of the neural basis of attention to date average effects across independently recorded neurons and across multiple trials. This is obviously artificial because attention has to be allocated on-the-fly, from moment-to-moment, not averaged across time. Trembly et al show that the current locus of attention can be decoded from ensembles of simultaneously recorded prefrontal cortex neurons from single trials. Decoding of these ensembles was stable over weeks. Nice.
2

Dec 2014

Communication through coherence with inter-areal delays

Miller Lab

Miller Laboratory, Neuroscience

Andre Bastos and colleagues review an update the communication-through-coherence (CTC) hypothesis. They propose that bi-directional cortical communication involves separate feedforward and feedback mechanisms that are separate both anatomically and spectrally.
26

Nov 2014

New paper: Task Dependence of Visual and Category Representations in Prefrontal and Inferior Temporal Cortices

Miller Lab

Miller Laboratory, Neuroscience

Task Dependence of Visual and Category Representations in Prefrontal and Inferior Temporal Cortices
Jillian L. McKee, Maximilian Riesenhuber, Earl K. Miller, and David J. Freedman

Visual categorization is an essential perceptual and cognitive process for assigning behavioral significance to incoming stimuli. Categorization depends on sensory processing of stimulus features as well as flexible cognitive processing for classifying stimuli according to the current behavioral context. Neurophysiological studies suggest that the prefrontal cortex (PFC) and the inferior temporal cortex (ITC) are involved in visual shape categorization. However, their precise roles in the perceptual and cognitive aspects of the categorization process are unclear, as the two areas have not been directly compared during changing task contexts. To address this, we examined the impact of task relevance on categorization-related activity in PFC and ITC by recording from both areas as monkeys alternated between a shape categorization and passive viewing tasks. As monkeys viewed the same stimuli in both tasks, the impact of task relevance on encoding in each area could be compared. While both areas showed task-dependent modulations of neuronal activity, the patterns of results differed markedly. PFC, but not ITC, neurons showed a modest increase in firing rates when stimuli were task relevant. PFC also showed significantly stronger category selectivity during the task compared with passive viewing, while task-dependent modulations of category selectivity in ITC were weak and occurred with a long latency. Finally, both areas showed an enhancement of stimulus selectivity during the task compared with passive viewing. Together, this suggests that the ITC and PFC show differing degrees of task-dependent flexibility and are preferentially involved in the perceptual and cognitive aspects of the categorization process, respectively.
20

Nov 2014

Theta Oscillations Modulate Attentional Search Performance Periodically

Miller Lab

Neuroscience

Several lines of evidence suggests that searching a visual scene depends on an intrinsic periodicity. We scan the scene by moving the spotlight of attention at regular intervals. For example, Buschman and Miller (2009) found neurophysiological evidence in the frontal eye fields for regular shifts of attention at 25 Hz (i.e., every 40 ms). Dugue et al (2014) have now found evidence in humans using EEG recording and TMS stimulation in humans. They found successful search was associated with oscillations and phase resetting at 6 Hz. TMS applied at different intervals found disruption of search at a periodicity corresponding to 6 Hz. This was slower than reported by Buschman and Miller (2009), but that could be because Dugue et al used a more difficult search task.

This paper:
Theta Oscillations Modulate Attentional Search Performance Periodically
Laura Dugué, Philippe Marque, and Rufin VanRullen Journal of Cognitive Neuroscience, 2014

For further reading:
Buschman, T.J. and Miller, E.K. (2009) Serial, covert, shifts of attention during visual search are reflected by the frontal eye fields and correlated with population oscillations. Neuron, 63: 386-396. View PDF »
18

Nov 2014

Earl Miller wins Bose Grant for high-risk, innovative research

Miller Lab

In The News, Miller Laboratory

Bose grants reward risk

Five innovative, high-risk projects launch with support from Prof. Amar G. Bose Research Grants

Radio New Zealand: Interview with Professor Earl Miller about Multi-tasking and technology

Originally aired on Afternoons, Tuesday 20 January 2015

Bose grants reward risk