Journalwatch: Neuroimage July 1, 2011

Three recommendations from this issue:

1. An information-theory driven study of the mirror neuron system. Fascinating.

Schippers and Keysers. Mapping the flow of information within the putative mirror neuron system during gesture observation. NeuroImage Volume 57, Issue 1, 1 July 2011, Pages 37-44

Abstract: The putative mirror neuron system may either function as a strict feed-forward system or as a dynamic control system. A strict feed-forward system would predict that action observation leads to a predominantly temporal→parietal→premotor flow of information in which a visual representation is transformed into motor-programs which contribute to action understanding. Instead, a dynamic feedback control system would predict that the reverse direction of information flow predominates because of a combination of inhibitory forward and excitatory inverse models. Here we test which of these conflicting predictions best matches the information flow within the putative mirror neuron system (pMNS) and between the pMNS and the rest of the brain during the observation of comparatively long naturalistic stretches of communicative gestures. We used Granger causality to test the dominant direction of influence. Our results fit the predictions of the dynamic feedback control system: we found predominantly an information flow within the pMNS from premotor to parietal and middle temporal cortices. This is more pronounced during an active guessing task than while passively reviewing the same gestures. In particular, the ventral premotor cortex sends significantly more information to other pMNS areas than it receives during active guessing than during passive observation.

The first paragraph of introduction shows their emphasis on thinking about information from the standpoint of prediction and observation (eg, a mismatch model), which is the view promoted for all of psychology on this site.

“Prediction of future events is a key feature of many cognitive abilities, such as language and action and has even been suggested as “one of the main unitary principles of cognition” (Bubic et al., 2010). Applied to the social domain, correct prediction of other’s behavior helps in understanding other’s intentions (Blakemore and Frith, 2005; Falck-Ytter et al., 2006), allows us to coordinate our behavior with others (Kokal et al., 2009; Sebanz et al., 2006) and is important for effective communication (Garrod and Pickering, 2009). Prediction of other’s behavior can be conceptualized on several levels and different timescales. For example, on a high cognitive level, humans can deliberately mentalize about beliefs and desires of others and how these will potentially influence their future behavior (Frith and Frith, 1999). On a lower cognitive level and a smaller time scale however, prediction of other’s behavior already occurs while the other person is still performing the action (Umiltà et al., 2001; Urgesi et al., 2010). The putative mirror neuron system (pMNS), a set of brain regions involved both in observing the actions of others and in programming similar actions (Gazzola and Keysers, 2008), has been suggested as a network that might be involved in predicting other people’s behavior on the basis of perceptual-motor mapping (Blakemore and Frith, 2005; Urgesi et al., 2010; Keysers and Perrett, 2004; Hesse et al., 2009; Kilner et al., 2007a,b; Lamm et al., 2007; Schubotz, 2007; Sebanz and Knoblich, 2009). The pMNS is a network in the human brain consisting of ventral and dorsal premotor cortex, anterior inferior parietal lobule and adjacent somatosensory area BA2 and middle temporal gyrus (Gazzola and Keysers, 2008; Keysers, 2009; Keysers and Gazzola, 2009). These areas of the human brain, normally associated with planning, preparation, execution and proprioception of our own actions, were found to be also involved in the hearing or observation of actions (Gazzola and Keysers, 2008; Chong et al., 2008; Dinstein et al., 2007; Filimon et al., 2007; Gazzola et al., 2006). These areas show a tight coupling between perception and action, which has led to the idea that we understand the actions of others in part by transforming them into the motor vocabulary of our own actions.”

2. An information theory-driven paper, getting at the idea that resting state may by effort by the brain to integrate past experience into a prediction of future.

Valentin Riedl (alpha) et al and Thomas R. Tölle (omega). Repeated pain induces adaptations of intrinsic brain activity to reflect past and predict future pain. Volume 57, Issue 1, 1 July 2011, Pages 206-213

Abstract: Recent neuroimaging studies have revealed a persistent architecture of intrinsic connectivity networks (ICNs) in the signal of functional magnetic resonance imaging (fMRI) of humans and other species. ICNs are characterized by coherent ongoing activity between distributed brain regions during rest, in the absence of externally oriented behavior. While these networks strongly reflect anatomical connections, the relevance of ICN activity for human behavior remains unclear. Here, we investigated whether intrinsic brain activity adapts to repeated pain and encodes an individual’s experience. Healthy subjects received a short episode of heat pain on 11 consecutive days. Across this period, subjects either habituated or sensitized to the painful stimulation. This adaptation was reflected in plasticity of a sensorimotor ICN (SMN) comprising pain related brain regions: coherent intrinsic activity of the somatosensory cortex retrospectively mirrored pain perception; on day 11, intrinsic activity of the prefrontal cortex was additionally synchronized with the SMN and predicted whether an individual would experience more or less pain during upcoming stimulation. Other ICNs of the intrinsic architecture remained unchanged. Due to the ubiquitous occurrence of ICNs in several species, we suggest intrinsic brain activity as an integrative mechanism reflecting accumulated experiences.

3. fMRI of the binding problem (modestly): 

Ping Wei, Hermann J. Müller and Stefan Pollmann. Neural correlates of binding features within- or cross-dimensions in visual conjunction search: An fMRI study. NeuroImage. Volume 57, Issue 1, 1 July 2011, Pages 235-241.

Abstract: The fMRI technique was used to investigate the functional neuroanatomy of binding features within- or cross-dimension during visual conjunction search. Participants were asked to perform feature search (FS; e.g., search for a vertical bar among tilted bars), within-dimension search (WS; e.g., search for an upright T among non-target oriented Ts and Ls), cross-dimension search (CS; e.g., search for an orange vertical bar among blue vertical bars and orange tilted bars), and complex search combining within- and cross-dimension features (WCS; e.g., search for an orange upright T among orange leftward Ts and blue Ls). Reaction times (RTs) taken to decide whether a target was present or absent were faster in the FS than in the WS, CS, and WCS conditions, but did not differ between the latter three conditions. Neuroimaging results revealed a set of fronto-parietal regions, including frontal eye field and intraparietal sulcus, to be consistently activated in conjunction search (WS, CS, and WCS) relative to feature search, suggesting that these regions play a more prominent role in matching visual input against the target template in conjunction search. Furthermore, left occipito-temporal cortex was more activated in within-dimension conjunction search, and bilateral intraparietal sulci were more activated in cross-dimension conjunction search. This suggests that features from the same dimension are ‘bound’ at a higher stage of the ventral pathway by conjoining the inputs from lower-level neurons, whereas neurons along the intraparietal sulcus appear to be necessary for discerning the presence of cross-dimensional conjunctions.

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