Physiological emotional under-arousal in individuals with mild head injury.

Primary Objectives: This study examined the potential emotional sequelae following self-reported mild head injury (MHI; e.g. 'altered state of consciousness' [ASC]) in university students with a particular focus on arousal status and responsivity to experimental manipulation of arousal.

Individualized model predicts brain current flow during transcranial direct-current stimulation treatment in responsive stroke patient.

Although numerous published reports have demonstrated the beneficial effects of transcranial direct-current stimulation (tDCS) on task performance, fundamental questions remain regarding the optimal electrode configuration on the scalp. Moreover, it is expected that lesioned brain tissue will influence current flow and should therefore be considered (and perhaps leveraged) in the design of individualized tDCS therapies for stroke. The current report demonstrates how different electrode configurations influence the flow of electrical current through brain tissue in a patient who responded positively to a tDCS treatment targeting aphasia.

Cerebral perfusion in chronic stroke: implications for lesion-symptom mapping and functional MRI.

Lesion-symptom mapping studies are based upon the assumption that behavioral impairments are directly related to structural brain damage. Given what is known about the relationship between perfusion deficits and impairment in acute stroke, attributing specific behavioral impairments to localized brain damage leaves much room for speculation, as impairments could also reflect abnormal neurovascular function in brain regions that appear structurally intact on traditional CT and MRI scans. Compared to acute stroke, the understanding of cerebral perfusion in chronic stroke is far less clear.

Transcranial direct current stimulation improves naming reaction time in fluent aphasia: a double-blind, sham-controlled study.

Background And Purpose: Previous evidence suggests that anodal transcranial direct current stimulation (A-tDCS) applied to the left hemisphere can improve aphasic participants' ability to name common objects. The current study further examined this issue in a more tightly controlled experiment in participants with fluent aphasia.

Methods: We examined the effect of A-tDCS on reaction time during overt picture naming in 8 chronic stroke participants.

Using transcranial direct-current stimulation to treat stroke patients with aphasia.

Background And Purpose: Recent research suggests that increased left hemisphere cortical activity, primarily of the left frontal cortex, is associated with improved naming performance in stroke patients with aphasia. Our aim was to determine whether anodal transcranial direct-current stimulation (tDCS), a method thought to increase cortical excitability, would improve naming accuracy in stroke patients with aphasia when applied to the scalp overlying the left frontal cortex.

Methods: Ten patients with chronic stroke-induced aphasia received 5 days of anodal tDCS (1 mA for 20 minutes) and 5 days of sham tDCS (for 20 minutes, order randomized) while performing a computerized anomia treatment.

Temporal order processing of syllables in the left parietal lobe.

Speech processing requires the temporal parsing of syllable order. Individuals suffering from posterior left hemisphere brain injury often exhibit temporal processing deficits as well as language deficits. Although the right posterior inferior parietal lobe has been implicated in temporal order judgments (TOJs) of visual information, there is limited evidence to support the role of the left inferior parietal lobe (IPL) in processing syllable order.

Activity in preserved left hemisphere regions predicts anomia severity in aphasia.

Understanding the neural mechanism that supports preserved language processing in aphasia has implications for both basic and applied science. This study examined brain activation associated with correct picture naming in 15 patients with aphasia. We contrasted each patient's activation to the activation observed in a neurologically healthy control group, allowing us to identify regions with unusual activity patterns.

Neural recruitment for the production of native and novel speech sounds.

Two primary areas of damage have been implicated in apraxia of speech (AOS) based on the time post-stroke: (1) the left inferior frontal gyrus (IFG) in acute patients, and (2) the left anterior insula (aIns) in chronic patients. While AOS is widely characterized as a disorder in motor speech planning, little is known about the specific contributions of each of these regions in speech. The purpose of this study was to investigate cortical activation during speech production with a specific focus on the aIns and the IFG in normal adults.

Cortical mapping of naming errors in aphasia.

Persons with aphasia vary greatly with regard to clinical profile; yet, they all share one common feature-anomia-an impairment in naming common objects. Previous research has demonstrated that particular naming errors are associated with specific left hemisphere lesions. However, we know very little about the cortical activity in the preserved brain areas that is associated with aphasic speech errors.

Treating visual speech perception to improve speech production in nonfluent aphasia.

Background And Purpose: Several recent studies have revealed modulation of the left frontal lobe speech areas not only during speech production but also for speech perception. Crucially, the frontal lobe areas highlighted in these studies are the same ones that are involved in nonfluent aphasia. Based on these findings, this study examined the utility of targeting visual speech perception to improve speech production in nonfluent aphasia.

Does aging influence people's metacomprehension? Effects of processing ease on judgments of text learning.

In 2 experiments, the authors investigated whether age-related differences exist in metacomprehension by evaluating predictions based on the ease-of-processing (EOP) hypothesis. According to this hypothesis, judgments of how well a text has been learned are based on how easily each text was processed; easier processing results in higher judgments. Participants read either sentence pairs or longer texts and judged their learning of each immediately afterward.

Does momentary accessibility influence metacomprehension judgments? The influence of study-judgment lags on accessibility effects.

In two experiments, we investigated momentary accessibility as a basis for metacomprehension judgments. Momentary accessibility has been cited as a major contributor to these judgments, yet the only previous investigation on the topic used judgments that were delayed a day after study, which have not been used in any other studies in the field and may be necessary for demonstrating accessibility-based effects. As expected, Experiment 1 demonstrated that the time between study and judgments moderates accessibility effects, with the relationship between judgments and access measures being substantially greater for delayed than for immediate judgments.