Neuronal effects following working memory training

AbstractThere is accumulating evidence that training working memory (WM) leads to beneficial effects in tasks that were not trained, but the mechanisms underlying this transfer remain elusive. Brain imaging can be a valuable method to gain insights into such mechanisms. Here, we discuss the impact of cognitive training on neural correlates with an emphasis on studies that implemented a WM intervention. We focus on changes in activation patterns, changes in resting state connectivity, changes in brain structure, and changes in the dopaminergic system. Our analysis of the existing literature reveals that there is currently no clear pattern of results that would single out a specific neural mechanism underlying training and transfer. We conclude that although brain imaging has provided us with information about the mechanisms of WM training, more research is needed to understand its neural impact

Third-person self-talk facilitates emotion regulation without engaging cognitive control: Converging evidence from ERP and fMRI.

Does silently talking to yourself in the third-person constitute a relatively effortless form of self control? We hypothesized that it does under the premise that third-person self-talk leads people to think about the self similar to how they think about others, which provides them with the psychological distance needed to facilitate self control. We tested this prediction by asking participants to reflect on feelings elicited by viewing aversive images (Study 1) and recalling negative autobiographical memories (Study 2) using either I or their name while measuring neural activity via ERPs (Study 1) and fMRI (Study 2). Study 1 demonstrated that third-person self-talk reduced an ERP marker of self-referential emotional reactivity (i.e., late positive potential) within the first second of viewing aversive images without enhancing an ERP marker of cognitive control (i.e., stimulus preceding negativity). Conceptually replicating these results, Study 2 demonstrated that third-person self-talk was linked with reduced levels of activation in an a priori defined fMRI marker of self-referential processing (i.e., medial prefrontal cortex) when participants reflected on negative memories without eliciting increased levels of activity in a priori defined fMRI markers of cognitive control. Together, these results suggest that third-person self-talk may constitute a relatively effortless form of self-control

Do Social Network Sites Enhance or Undermine Subjective Well‐Being? A Critical Review

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/136039/1/sipr12033.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/136039/2/sipr12033_am.pd

Cognitive load and maintenance rehearsal

In recent years there has been a good deal of debate about the role of rote, repetitive rehearsal (called Type I or maintenance rehearsal) on the establishment of memory traces that outlast the rehearsal process itself. One advance in the technology used to study this problem is the operational definition of maintenance rehearsal proposed by Glenberg and Adams (1978, Journal of Verbal Learning and Verbal Behavior, 17, 455-463). These authors argued that maintenance rehearsal should be defined as the continuous maintenance of information in memory using minimal cognitive capacity. Here this definition was adopted and extended in a paradigm in which the mental resources devoted to maintenance rehearsal could be systematically varied. The experiment revealed that there is, indeed, an effect of maintenance rehearsal on long-term recognition performance and that this effect depends on the mental resources devoted to the rehearsal process.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/24749/1/0000171.pd

The brightness clustering transform and locally contrasting keypoints

In recent years a new wave of feature descriptors has been presented to the computer vision community, ORB, BRISK and FREAK amongst others. These new descriptors allow reduced time and memory consumption on the processing and storage stages of tasks such as image matching or visual odometry, enabling real time applications. The problem is now the lack of fast interest point detectors with good repeatability to use with these new descriptors. We present a new blob- detector which can be implemented in real time and is faster than most of the currently used feature-detectors. The detection is achieved with an innovative non-deterministic low-level operator called the Brightness Clustering Transform (BCT). The BCT can be thought as a coarse-to- fine search through scale spaces for the true derivative of the image; it also mimics trans-saccadic perception of human vision. We call the new algorithm Locally Contrasting Keypoints detector or LOCKY. Showing good repeatability and robustness to image transformations included in the Oxford dataset, LOCKY is amongst the fastest affine-covariant feature detectors

Age Differences in Behavior and PET Activation Reveal Differences in Interference Resolution in Verbal Working Memory

Older adults were tested on a verbal working memory task that used the item-recognition paradigm. On some trials of this task, response-conflict was created by presenting test-items that were familiar but were not members of a current set of items stored in memory. These items required a negative response, but their familiarity biased subjects toward a positive response. Younger subjects show an interference effect on such trials, and this interference is accompanied by activation of a region of left lateral prefrontal cortex. However, there has been no evidence that the activation in this region is causally related to the interference that the subjects exhibit. In the present study, we demonstrate that older adults show more behavioral interference than younger subjects on this task, and they also show no reliable activation at the same lateral prefrontal site. This leads to the conclusion that this prefrontal site is functionally involved in mediating resolution among conflicting responses or among conflicting representations in working memory

Inhibitory Selection Mechanisms in Clinically Healthy Older and Younger Adults

OBJECTIVE: Declines in working memory are a ubiquitous finding within the cognitive-aging literature. A unitary inhibitory selection mechanism that serves to guide attention toward task-relevant information and resolve interference from task-irrelevant information has been proposed to underlie such deficits. However, inhibition can occur at multiple time points in the memory-processing stream. Here, we tested whether the time point at which inhibition occurs in the memory-processing stream affects age-related memory decline. METHOD: Clinically healthy younger (n = 23) and older (n = 22) adults performed two similar item-recognition working memory tasks. In one task, participants received an instruction cue telling them which words to attend to followed by a memory set, promoting perceptual inhibition at the time of encoding. In the other task, participants received the instruction cue after they received the memory set, fostering inhibition of items already in memory. RESULTS: We found that older and younger adults differed in their ability to inhibit items both during encoding and when items had to be inhibited in memory but that these age differences were exaggerated when irrelevant information had to be inhibited from memory. These results provide insights into the mechanisms that support cognitive changes to memory processes in healthy aging

Assessing automaticity

We propose two principles that should be followed in the study of automaticity for cognitive processes. Both follow from the general rule that experimental research should be guided by a model of the task in question, frequently a process model. The first is that the concept of automaticity is best applied to component processes of complex behaviors rather than to behaviors as a whole. The second is that the criteria chosen for the identification of automaticity should be motivated by the processes in question. Examples are discussed of research programs that are relevant to each principle.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/25469/1/0000009.pd