Decreased parahippocampal activity in associative priming: evidence from an event-related fMRI study

In recent years, there has been intense debate on the neural basis of associative priming, particularly on the role of the medial temporal lobe (MTL) in retrieving associative information without awareness. In this study, event-related fMRI was used while healthy subjects performed a perceptual identification task on briefly presented unrelated word pairs and an associative recognition memory task. Contamination of priming by explicit memory was successfully controlled, as associative priming and explicit memory were dissociated on the behavioral level. The fMRI results showed a functional dissociation within the MTL with respect to associative priming effects. The right parahippocampal cortex, but not the hippocampus, showed decreased activation for old vs. new pairs and old vs. recombined pairs (associative priming). The bilateral hippocampus and the right parahippocampal cortex were involved in explicit associative memory. These data provide evidence that subregions of the MTL participate in associative priming even when explicit involvement was controlled. Thus, different regions within the MTL play distinct roles in explicit and implicit associative memory.     

Effects of rater goals on rating patterns: evidence from an experimental field study

The goal-based perspective of performance appraisals suggests that raters who pursue different goals give different performance ratings. Yet previous studies have not provided strong empirical evidence that there are different impacts of different goals on mean rating and discriminability, nor have they provided evidence of a goal-rating causality. The authors extend the literature by manipulating rater goals in the context of peer evaluations of graded group projects with a sample of 104 undergraduate students. They find that (a) pursuing a harmony goal increased mean rating and decreased discriminability, and (b) pursuing a fairness goal increased mean rating and decreased discriminability when the group projects had not ended and increased mean rating but did not change discriminability when the group projects had ended.     

Neurobehavioral evidence for individual differences in canine cognitive control: an awake fMRI study

Based on behavioral evidence, the domestic dog has emerged as a promising comparative model of human self-control. However, while research on human inhibition has probed heterogeneity and neuropathology through an integration of neural and behavioral evidence, there are no parallel data exploring the brain mechanisms involved in canine inhibition. Here, using a combination of cognitive testing and awake neuroimaging in domestic dogs, we provide evidence precisely localizing frontal brain regions underpinning response inhibition in this species and demonstrate the dynamic relationship between these regions and behavioral measures of control. Thirteen dogs took part in an in-scanner go/no-go task and an out-of-scanner A-not-B test. A frontal brain region was identified showing elevated neural activity for all subjects during successful inhibition in the scanner, and dogs showing greater mean brain activation in this region produced fewer false alarms. Better performance in the go/no-go task was also correlated with fewer errors in the out-of-scanner A-not-B test, suggesting that dogs show consistent neurobehavioral individual differences in cognitive control, as is seen in humans. These findings help establish parity between human and canine mechanisms of self-control and pave the way for future comparative studies examining their function and dysfunction.     

Dissociable patterns of brain activity during comprehension of rapid and syntactically complex speech: evidence from fMRI

Sentence comprehension is a complex task that involves both language-specific processing components and general cognitive resources. Comprehension can be made more difficult by increasing the syntactic complexity or the presentation rate of a sentence, but it is unclear whether the same neural mechanism underlies both of these effects. In the current study, we used event-related functional magnetic resonance imaging (fMRI) to monitor neural activity while participants heard sentences containing a subject-relative or object-relative center-embedded clause presented at three different speech rates. Syntactically complex object-relative sentences activated left inferior frontal cortex across presentation rates, whereas sentences presented at a rapid rate recruited frontal brain regions such as anterior cingulate and premotor cortex, regardless of syntactic complexity. These results suggest that dissociable components of a large-scale neural network support the processing of syntactic complexity and speech presented at a rapid rate during auditory sentence processing.     

Cephalopod consciousness: behavioural evidence

Behavioural evidence suggests that cephalopod molluscs may have a form of primary consciousness. First, the linkage of brain to behaviour seen in lateralization, sleep and through a developmental context is similar to that of mammals and birds. Second, cephalopods, especially octopuses, are heavily dependent on learning in response to both visual and tactile cues, and may have domain generality and form simple concepts. Third, these animals are aware of their position, both within themselves and in larger space, including having a working memory of foraging areas in the recent past. Thus if using a 'global workspace' which evaluates memory input and focuses attention is the criterion, cephalopods appear to have primary consciousness.     

Lying about facial recognition: an fMRI study

Novel deception detection techniques have been in creation for centuries. Functional magnetic resonance imaging (fMRI) is a neuroscience technology that non-invasively measures brain activity associated with behavior and cognition. A number of investigators have explored the utilization and efficiency of fMRI in deception detection. In this study, 18 subjects were instructed during an fMRI "line-up" task to either conceal (lie) or reveal (truth) the identities of individuals seen in study sets in order to determine the neural correlates of intentionally misidentifying previously known faces (lying about recognition). A repeated measures ANOVA (lie vs. truth and familiar vs. unfamiliar) and two paired t-tests (familiar vs. unfamiliar and familiar lie vs. familiar truth) revealed areas of activation associated with deception in the right MGF, red nucleus, IFG, SMG, SFG (with ACC), DLPFC, and bilateral precuneus. The areas activated in the present study may be involved in the suppression of truth, working and visuospatial memories, and imagery when providing misleading (deceptive) responses to facial identification prompts in the form of a "line-up".     

Prosodic processing by children: an fMRI study

Prosodic information in the speech signal carries information about linguistic structure as well as emotional content. Although children are known to use prosodic information from infancy onward to assist linguistic decoding, the brain correlates of this skill in childhood have not yet been the subject of study. Brain activation associated with processing of linguistic prosody was examined in a study of 284 normally developing children between the ages of 5 and 18 years. Children listened to low-pass filtered sentences and were asked to detect those that matched a target sentence. fMRI scanning revealed multiple regions of activation that predicted behavioral performance, independent of age-related changes in activation. Likewise, age-related changes in task activation were found that were independent of differences in task accuracy. The overall pattern of activation is interpreted in light of task demands and factors that may underlie age-related changes in task performance.     

Decision making under risk condition in patients with Parkinson's disease: a behavioural and fMRI study

We aimed to study whether previously described impairment in decision making under risky conditions in patients with Parkinson's disease (PD) is affected by deficits in using information about potential incentives or by processing feedback (in terms of fictitious gains and losses following each decision). Additionally, we studied whether the neural correlates of using explicit information in decision making under risk differ between PD patients and healthy subjects. We investigated ten cognitively intact PD patients and twelve healthy subjects with the Game of Dice Task (GDT) to assess risky decision making, and with an fMRI paradigm to analyse the neural correlates of information integration in the deliberative decision phase. Behaviourally, PD patients showed selective impairment in the GDT but not on the fMRI task that did not include a feedback component. Healthy subjects exhibited lateral prefrontal, anterior cingulate and parietal activations when integrating decision-relevant information. Despite similar behavioural patterns on the fMRI task, patients exhibited reduced parietal activation. Behavioural results suggest that PD patients' deficits in risky decision making are dominated by impaired feedback utilization not compensable by intact cognitive functions. Our fMRI results suggest similarities but also differences in neural correlates when using explicit information for the decision process, potentially indicating different strategy application even if the interfering feedback component is excluded.     

Remembering pleasure and personal meaning from episodes of intrinsic motivation: an fMRI study

Motivation and Emotion - To decide whether or not to participate in an upcoming activity, people can use their memories of intrinsically-motivating or non-intrinsically-motivating experiences...     

Dual-route processing of complex words: New fMRI evidence from derivational suffixation

Many behavioral models of the comprehension of suffixed words assume a dual-route mechanism in which these words are accessed sometimes from the mental lexicon as whole units and sometimes in terms of their component morphemes (such as happi+=ness). In related neuropsychological work, Ullman et al. (1997) proposed a dual-route model for past tense processing, in which the lexicon (used for access to irregularly inflected forms) corresponds to declarative memory and a medial temporal/ parietal circuit, and the rule system (used for computation of regularly inflected forms) corresponds to procedural memory and a frontal (including Broca’s area)/basal ganglia circuit. We used functional MRI and a memory encoding task to test this model for derivationally suffixed words, comparing those words that show evidence of decompositional processing in behavioral studies (-ness, -less, and -able words) with derived words that do not show decomposition effects (-ity and -ation words). By examining Broca’s area and the basal ganglia as regions of interest, we found that “decomposable” derived and inflected words showed increases in activity relative to nondecomposable suffixed words. Results support a dual-route model of lexical access of complex words that is consistent with the Ullman et al. proposal.     

Neuroanatomical distribution of five semantic components of verbs: evidence from fMRI

The Simulation Framework, also known as the Embodied Cognition Framework, maintains that conceptual knowledge is grounded in sensorimotor systems. To test several predictions that this theory makes about the neural substrates of verb meanings, we used functional magnetic resonance imaging (fMRI) to scan subjects' brains while they made semantic judgments involving five classes of verbs-specifically, Running verbs (e.g., run, jog, walk), Speaking verbs (e.g., shout, mumble, whisper), Hitting verbs (e.g., hit, poke, jab), Cutting verbs (e.g., cut, slice, hack), and Change of State verbs (e.g., shatter, smash, crack). These classes were selected because they vary with respect to the presence or absence of five distinct semantic components-specifically, ACTION, MOTION, CONTACT, CHANGE OF STATE, and TOOL USE. Based on the Simulation Framework, we hypothesized that the ACTION component depends on the primary motor and premotor cortices, that the MOTION component depends on the posterolateral temporal cortex, that the CONTACT component depends on the intraparietal sulcus and inferior parietal lobule, that the CHANGE OF STATE component depends on the ventral temporal cortex, and that the TOOL USE component depends on a distributed network of temporal, parietal, and frontal regions. Virtually all of the predictions were confirmed. Taken together, these findings support the Simulation Framework and extend our understanding of the neuroanatomical distribution of different aspects of verb meaning.     

Language as a cultural vessel in online servicescapes: Its impact on consumers' perceived risk,attitudes, and behavioural intentions

Globalisation and the broader use of the Internet have led both academia and professionals to dedicate a great deal of attention to the analysis of the cultural differences that exist within a market and between different markets. Language emerges as a relevant issue in current marketing and communication management environments, especially in online servicescape. Following this premise, the current paper examines the role of language as a vessel of cultural values, namely, individualism and uncertainty avoidance, and its impact on consumer's perceived risk, attitudes, and behavioural intentions in online servicescape. To address this objective, an experimental design was performed. The sample comprised 491 Internet users from 2 different national cultures (British and Spanish). Users were asked to browse an experimental website in their native or first language, whereas the other half of the sample browsed in their second language (British subjects browsing in Spanish and vice versa). The unique contribution of this study lies in demonstrating that online information processing is moderated by the language by which users elaborate information and their cultural values in terms of the dimensions of individualism and uncertainty avoidance. The findings provide valuable insights into the role of language in international marketing strategies, as well as in multicultural and cross‐cultural integrated marketing communications. In this regard, marketers must acknowledge the symbolic cues of language and the competitive advantage that might derive from a strategic language choice to evoke emotions and forge attitudes that are consistent with brand and corporate values.     

Attention and semantic processing during speech: an fMRI study

This fMRI study was conducted to investigate whether language semantics is processed even when attention is not explicitly directed to word meanings. In the “unattended” condition, the subjects performed a visual detection task while hearing semantically related and unrelated word pairs. In the “phoneme” condition, the subjects made phoneme judgements between prime and target words, and in the “word” condition, they indicated whether the words in each word pair were semantically related or unrelated. In the word condition, stronger activity was obtained for unrelated than related words in the superior temporal gyrus/sulcus (STG/STS), lingual/fusiform gyri and cuneus, whereas in the phoneme condition no such effect was observed. However, during the unattended condition, stronger activity was found in the right STG. Our results suggest that both semantic judgement of word pairs and their passive hearing activate the same neural networks but this activation is more restricted in the passive hearing.     

The right hemisphere as an anomaly detector: evidence from visual perception

V. S. Ramachandran (1998) has suggested that the right hemisphere, which tends to be specialized for the analysis of global-level information, serves as an anomaly detector. Its role is to judge whether a given percept is possible and whether there are elements of that percept that seem incongruent with the other elements. In contrast, the left hemisphere tends to create a "story" to make sense of the incongruities. In the current study, pictures of possible or impossible objects were displayed for brief exposure durations to either the left visual field/right hemisphere or to the right visual field/left hemisphere). The results provide tentative support for the work of Ramachandran. In male participants, the right hemisphere was superior to the left in detecting impossible objects.     

Healthy brooders employ more attentional resources when disengaging from the negative: an event-related fMRI study

Depressive brooding is considered a maladaptive ruminative-thinking style that has been shown to be highly correlated with major depression. The present study in healthy participants employed event-related fMRI to uncover the neural underpinnings of emotional disengagement as it relates to depressive brooding. Thirty-four healthy, never depressed individuals performed an emotional go/no-go task with a rapid presentation of emotional faces. We focused on the contrast of inhibiting sad (happy/no-go) versus inhibiting happy (sad/no-go) information. This contrast allowed us to assess possible difficulties in disengaging from emotionally negative, as compared with emotionally positive, faces. At the behavioral level, only in high brooders were higher self-reported brooding scores correlated with more errors when sad information was inhibited, relative to happy information. At the neural level, across all participants, brooding scores were positively correlated with activity in the right dorsolateral prefrontal cortex (DLPFC; BA 46), implying that high brooders show higher DLPFC involvement when successfully disengaging from a series of negative stimuli. These results may suggest that healthy individuals who report a high brooding thinking style need to recruit more attentional control in order to disengage successfully from negative information, in a way that may be related to emotion regulation strategies. These mechanisms might protect them from developing depressive symptoms.     

Attentional control in the aging brain: insights from an fMRI study of the stroop task

Several recent studies of aging and cognition have attributed decreases in the efficiency of working memory processes to possible declines in attentional control, the mechanism(s) by which the brain attempts to limit its processing to that of task-relevant information. Here we used fMRI measures of neural activity during performance of the color-word Stroop task to compare the neural substrates of attentional control in younger (ages: 21-27 years old) and older participants (ages: 60-75 years old) during conditions of both increased competition (incongruent and congruent neutral) and increased conflict (incongruent and congruent neutral). We found evidence of age-related decreases in the responsiveness of structures thought to support attentional control (e.g., dorsolateral prefrontal and parietal cortices), suggesting possible impairments in the implementation of attentional control in older participants. Consistent with this notion, older participants exhibited more extensive activation of ventral visual processing regions (i.e., temporal cortex) and anterior inferior prefrontal cortices, reflecting a decreased ability to inhibit the processing of task-irrelevant information. Also, the anterior cingulate cortex, a region involved in evaluatory processes at the level of response (e.g., detecting potential for error), showed age-related increases in its sensitivity to the presence of competing color information. These findings are discussed in terms of newly emerging models of attentional control in the human brain.     

The effects of attention on speech perception: an fMRI study

Focusing of attention to a specific speech source plays an important role in everyday speech perception. However, little is known of the neuronal substrates of focused attention in speech perception. Thus, the present study investigated the effects on neuronal activation of directed attention to auditory stimuli that differed in semantic content. Using an event-related fMRI protocol, single vowels, three-phoneme pseudowords and three- and four-phoneme real nouns and words were randomly presented to the subjects during four different instructional conditions. One condition was passive listening without any specific instructions of focusing of attention. The other conditions were attention focused on either the vowels, the pseudowords or the words. Thus, the acoustic stimulation was constant across conditions. The subjects were 13 healthy adults. Functional MRI was performed with a 1.5 T scanner, using an event-related design. During passive listening, there were significant activations bilaterally in the superior temporal gyrus. Instruction to attend to the pseudowords caused activation in middle temporal lobe areas, extending more anterior compared to the activations seen during passive listening. Instruction to attend to the vowel sounds caused an increase in activation in the superior/medial temporal lobe, with a leftward asymmetry. Instruction to attend to the words caused a leftward asymmetry, particularly in the middle and superior temporal gyri. It is concluded that attention plays a modulatory role in neuronal activation to speech sounds, producing specific activations to specific stimulus categories that may act to facilitate speech perception.     

Meditation-specific prefrontal cortical activation during acem meditation: an fMRI study

Some of the most popular meditation practices emphasize a relaxed focus of attention in which thoughts, images, sensations, and emotions may emerge and pass freely without actively controlling or pursuing them. Several recent studies show that meditation activates frontal brain areas associated with attention focusing and physical relaxation. The objective of the present study was to assess whether brain activation during relaxed focusing on a meditation sound could be distinguished from similar, concentrative control tasks. Brain activation was measured with functional magnetic resonance imaging (fMRI) in experienced practitioners of Acem meditation. Bilateral areas of the inferior frontal gyrus (BA47) were significantly more activated during repetition of a meditation sound than during concentrative meditation-like cognitive tasks. Meditation-specific brain activation did not habituate over time, but increased in strength with continuous meditation bouts. These observations suggest that meditation with a relaxed focus of attention may activate distinct areas of the prefrontal cortex, with implications for the understanding of neurobiological correlates of meditation.     

Connectivity among semantic associates: an fMRI study of semantic priming

Semantic priming refers to a reduction in the reaction time to identify or make a judgment about a stimulus that has been immediately preceded by a semantically related word or picture and is thought to result from a partial overlap in the semantic associates of the two words. A semantic priming lexical decision task using spoken words was presented in event-related fMRI and behavioral paradigms. Word pairs varied in terms of semantic relatedness and the connectivity between associates. Thirteen right-handed subjects underwent fMRI imaging and 10 additional subjects were tested in a behavioral version of the semantic priming task. It was hypothesized priming would be greatest, reaction time fastest, and cortical activation reduced the most for related word pairs of high connectivity, followed by related word pairs of low connectivity, and then by unrelated word pairs. Behavioral and fMRI results confirmed these predictions. fMRI activity located primarily in bilateral posterior superior and middle temporal regions showed modulation by connectivity and relatedness. The results suggest that these regions are involved in semantic processing.