Koralek et al show learning-related increases in oscillatory coherence between the motor cortex and striatum during learning. The increase in coherence was seen for neurons related to behavior. This supports the notion that oscillatory coherence plays a role in forming functional networks.
Pesenson, Cohen, and Voytek review methods for linking nonlinear oscillatory neural dynamics, in particular oscillatory phase, to behavior.
Linking Nonlinear Neural Dynamics to Single-Trial Human Behavior
Lee, Whittington, and Kopell review recent studies of the role of beta-band oscillations in top-down control of attention and model it. In their model, top-down beta rhythms activate layer-specific ascending projections that mediate biased competition. Interneurons resonate with the beta oscillations and help modulate superficial layer activity according to attentional demands.
A review of the groundbreaking work of Patricia Goldman-Rakic by Amy Arnsten
Lopour et al report evidence for phase coding in the human temporal lobe. They recorded local field potentials (LFPs) in patients during performance of a card matching task. Classification of correct/incorrect responses was better when LFP phase was taken into account. The phases aligned just before the the two cards were compared and then diverged to code the response.
Vinck, Womelsdorf, Fries review the role of gamma band synchronization in information transfer in the cortex. They argue that due to feedforward coincidence detection and phase-coupling, gamma synchronization is important for flexible routing of information and may be an important determinant of spike rate coding.
Christian Ruff pays tribute to the late, great, Jon Driver by reviewing neural mechanisms of top-down control of attention and memory.
A review in Science of Sue Corkin’s book on the famous neuropsychology patient H.M., who could no longer form memories after his hippocampus was removed.
Permanent Present Tense The Unforgettable Life of the Amnesic Patient, H.M. by Suzanne Corkin Basic Books, New York, 2013. 400 pp. $28.99, C$32. ISBN 9780465031597. Allen Lane, London. £20. ISBN 9781846142710.
Jutras et al find a relationship between hippocampal theta and visual exploration via saccadic eye movements. Saccades caused a theta reset that was predictive of subsequent recognition of visual images. Enhanced theta power before stimulus onset was also predictive of recognition.
Eldar et al show that neural gain influences learning style. Subjects learned associations between pictures and reward. The association could be based on different stimulus dimensions and different people had different predispositions for one dimension or the other. Eldar et al assessed neural gain by pupil dilation (which is correlated with locus coeruleus norepinephrine activity) and found that the higher the gain, the more likely subjects were to follow their predispositions. The increase in gain was thought to boost the asymmetry of strength between different functional networks which are responsible for the predisposition in learning style.
Miller Lab graduate student Simon Kornblith publishes a paper in Neuron from work in his old lab. By combining FMRI with electrode recording and stimulation, they found an area in the occipitotemporal cortex that has many scene-selective neurons, the lateral place patch (LPP). By stimulating it, they discover connections to several other cortical areas, including a medial place patch (MPP) in the parahippocampal gyrus. Elegant and important work, Simon, congratulations! Now, get back to work. 🙂
A flurry of articles about Picower Institute’s Susumu Tonegawa’s paper implanting false memories in the mouse brain. They identified and tagged a memory engram for one environment, then activated that engram in a different environment while pairing it with shock. Later, the animals showed fear in the first environment as if they were shocked there.
The Guardian
The New York Times
The cover of Science
The journal Cortex will peer-review your experimental plan. If accepted, they agree to publish your results, regardless of how they turn out. But you must release your raw data so others can have at it.
Article in the Guardian
Shenhav, Botvinick, and Cohen tie together a number of observations and notions into a new theory of ACC function: allocation of control based on an evaluation of the expected value of control (EVC).
Dave Eagleman spells it out for us.
Dipoppa and Gutkin propose a model of working memory in which gamma-beta oscillations gates access, theta oscillations protects working memory from distractions, and alpha oscillations clears out old memories.
This is consistent with our observations that beta helps from ensembles for rules held in working memory while alpha clears out a dominant ensemble so that a weaker one can be used:
Buschman, T.J., Denovellis, E.L., Diogo, C., Bullock, D. and Miller, E.K. (2012) Synchronous oscillatory neural ensembles for rules in the prefrontal cortex. Neuron, 76: 838-846. View PDF
Zhang et al studied rule-based behavior by either having human subjects choose the rule themselves or by instructing them to the rule. They found context-dependent and context-independent (chosen vs instructed) rule representations in frontal and parietal cortex. This gives insight into the architecture of cognitive control.
Cowell and Cottrell trained a computational model on images used in fMRI studies of object and face processing. They used multivariate pattern analysis and were able to replicate evidence for a specialized face area even though the model had no specialized processing for faces. The authors suggest that fMRI evidence for a specialized face area should be interpreted with caution.
Excellent review of an important topic: Working memory capacity. The limitation in working memory capacity is the most objective, easily measured, and tractable property of conscious thought..
Luck and Vogel (2013)
Miller Lab work cited:
Siegel, M., Warden, M.R., and Miller, E.K. (2009) Phase-dependent neuronal coding of objects in short-term memory. Proceedings of the National Academy of Sciences, 106: 21341-21346. View PDF »
Hirabayashi et al observed microcircuits for object association using multiple single-unit recordings in temporal cortex. This suggests that microcircuits creates precursor representations for a given feature in previous areas in the cortical hierarchy.
Peter Lakatos and Charlie Schroeder have conducted elegant work showing that the brain entrains its rhythms to attended sensory inputs. Here, Lakatos et al show that normal human subjects show increased rhythmic entrainment with increasing task demands, By contrast, schizophrenic patients are less able to match their brain rhythms to attended stimuli, even when the task is highly demanding.
Miller Lab work cited:
Buschman, T.J. and Miller, E.K. (2007) Top-down versus bottom-up control of attention in the prefrontal and posterior parietal cortices. Science. 315: 1860-1862 The Scientist’s “Hot Paper” for October 2009. View PDF »
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 »
Hohl et al use a task with richer behavioral output to better establish a link between neural activity and behavior.
Your prefrontal cortex becomes less resistant to stress as you age. McEwen and Morrison tell you all about it.
The 2013 Annual Review of Neuroscience is here. It includes a very nice review of the role of the prefrontal cortex in visual attention by Squire et al
Discovery that some seizures arise in glial cells could offer new targets for epilepsy treatment. MIT News Release