Motor functions of the Broca's region

Broca's region in the dominant cerebral hemisphere is known to mediate the production of language but also contributes to comprehension. This region evolved only in humans and is constituted of Brodmann's areas 44 and 45 in the inferior frontal gyrus. There is, however, evidence that Broca's region overlaps, at least in part, with the ventral premotor cortex. We summarize the evidence that the motor related part of Broca's area is localized in the opercular portion of the inferior frontal cortex, mainly in area 44 of Brodmann. According to our own data, there seems to be a homology between Brodmann area 44 in humans and the monkey area F5. The non-language related motor functions of Broca's region comprise complex hand movements, associative sensorimotor learning and sensorimotor integration. Brodmann's area 44 is also a part of a specialized parieto-premotor network and interacts significantly with the neighboring premotor areas.     

Architecture and organizational principles of Broca's region

Identifying cortical areas for language and speech processing is a prerequisite for cognitive neuroscience and clinical research. Although Broca's region is one of the essential nodes in the language network, its anatomical constituents are ill-defined and multiple definitions of Broca's region exist. Sanides' concept of microstructural gradations interpreted Broca's region as developing from neighboring motor, dorsolateral-prefrontal, and insular cortices. Recent mapping approaches based on cytoarchitecture, transmitter receptor distribution, and connectivity revealed a highly differentiated segregation of this region far beyond Brodmann's classical scheme. This novel segregational concept of structural and functional architecture more adequately reflects the various functions of Broca's region in cognitive and/or linguistic processes.     

Principles that are invoked in the acquisition of words, but not facts

A controversial question is whether language acquisition is the result of domain-general or domain-specific principles. Focusing on word-learning, Markson and Bloom (Nature 385(6619) (1997) 813) recently argued that the ability to learn and retain new words (count nouns) is the result of abilities that are not specific to language. In the current experiment, we replicate their empirical finding, but challenge their domain-general interpretation by highlighting a crucial distinction between the principles involved in learning a count noun, as compared to learning a fact. The current results confirm that learning count nouns and facts involve (at least) two common components: establishing a mapping to a designated individual, and retaining this mapping over time. However, these results go further to document that the processes invoked in the acquisition of words differ from those invoked in the acquisition of facts. Children spontaneously and systematically extended a novel count noun exclusively to other members of the same category, but revealed no such systematicity when extending a fact. This illustrates that there are principles that are invoked in learning a novel count noun that are not invoked in learning a fact.     

How not to be seen: the contribution of similarity and selective ignoring to sustained inattentional blindness

When people attend to objects or events in a visual display, they often fail to notice an additional, unexpected, but fully visible object or event in the same display. This phenomenon is now known as inattentional blindness . We present a new approach to the study of sustained inattentional blindness for dynamic events in order to explore the roles of similarity, distinctiveness, and attentional set in the detection of unexpected objects. In Experiment 1, we found that the similarity of an unexpected object to other objects in the display influences attentional capture: The more similar an unexpected object is to the attended items, and the greater its difference from the ignored items, the more likely it is that people will notice it. Experiment 2 explored whether this effect of similarity is driven by selective ignoring of irrelevant items or by selective focusing on attended items. The results of Experiment 3 suggest that the distinctiveness of the unexpected object alone cannot entirely account for the similarity effects found in the first two experiments; when attending to black items or white items in a dynamic display, nearly 30% of observers failed to notice a bright red cross move across the display, even though it had a unique color, luminance, shape, and motion trajectory and was visible for 5 s. Together, the results suggest that inattentional blindness for ongoing dynamic events depends both on the similarity of the unexpected object to the other objects in the display and on the observer's attentional set.     

Retrieval-induced forgetting of arithmetic facts but not rules

Retrieval of a multiplication fact (2×6 =12) can disrupt retrieval of its addition counterpart (2+6=8). We investigated whether this retrieval-induced forgetting effect applies to rule-governed arithmetic facts (i.e., 0×N=0, 1×N=N). Participants (n=40) practised rule-governed multiplication problems (e.g., 1×4, 0×5) and multiplication facts (e.g., 2×3, 4×5) for four blocks and then were tested on the addition counterparts (e.g., 1+4, 0+5, 2+3, 4+5) and control additions. Increased addition response times and errors relative to controls occurred only for problems corresponding to multiplication facts, with no problem-specific effects on addition counterparts of rule-governed multiplications. In contrast, the rule-governed 0+N problems provided evidence of generalisation of practice across items, whereas the fact-based 1+N problems did not. These findings support the theory that elementary arithmetic rules and facts involve distinct memory processes, and confirmed that previous, seemly inconsistent findings of RIF in arithmetic owed to the inclusion or exclusion of rule-governed problems.     

Sentence comprehension by Broca's aphasics: Effects of some suprasegmental variables

Three subtests of comprehension (one of varying sentential stress, one of shifting juncture, and one of applying emphatic stress to functors) were administered to eight Broca's aphasics and eight controls to determine the effects of stress and juncture on disambiguation of these sentences. Data indicated that the aphasic group performed significantly worse than the normals on all three subtests of comprehension. In addition, there was a strong positive correlation between severity of aphasia and error scores for all three tests. Results are discussed in relation to intact-vs.-disordered comprehension.     

Agrammatic Broca's aphasia is not associated with a single pattern of comprehension performance

One influential hypothesis posits that the brain regions implicated in Broca's aphasia are responsible for specific syntactic operations that are necessary for the comprehension and production of sentences (Grodzinsky, 1986, 1990, in press). The empirical basis of this hypothesis is the claim that Broca's aphasics have no difficulty understanding sentences in the active voice (and other "canonical" sentence types, such as subject relatives and clefts with negative predicates), but perform at chance level with passive voice constructions (and other "noncanonical" sentences such as object-gap relatives and object clefts). In the face of well-established results indicating that Broca's aphasics can exhibit several different performance patterns on these sentence types, Grodzinsky, Pi?ango, Zurif, and Drai (1999) argued that these conflicting results do not challenge the theory when the data are analyzed appropriately. They carried out a creative statistical analysis of the comprehension performance of published cases of Broca's aphasia and concluded that all of these cases are in agreement with the predicted pattern: chance on passives and 100% correct on actives. Here we show that the statistical reasoning adopted by Grodzinsky et al. (1999) is flawed. We also show that the comprehension performance of a substantial number of the Broca's aphasics in their own sample does not conform to the pattern required. Rather, contrary to these authors' claim, Broca's aphasia is not associated with a consistent pattern of sentence comprehension performance, but allows for a number of distinct patterns in different patients.     

Comprehension of contrastive stress by Broca's aphasics.

Comprehension of stress as a determiner of reference for pronouns was compared in eight patients with Broca's aphasia (BA) and five age-matched control subjects. The subjects were asked to listen to sentences in which the stressed or unstressed condition of the pronoun was a critical criterion for the establishment of reference. For each sentence, subjects were shown three pictures and asked to point to the correct referent of the pronoun. While the controls were nearly perfect in both the stressed and unstressed conditions, BA patients were significantly worse than normals, showing chance performance in both cases. However, a significant disparity was found in the BA patients' selection of the object NP as the referent under stressed and unstressed conditions, indicating that BA subjects are, indeed, sensitive to the stress patterns of pronouns. It was thus hypothesized that the BA patients' chance performance was the result of an inability to implement their knowledge of stress during the processing of sentences involving discourse-related linguistic operations, such as the establishment of pronoun reference (Grodzinsky, Wexler, Chien, Marakovitz, & Solomon, 1993). To test this hypothesis, a second experiment was conducted in which discourse-related operations were eliminated. In this second experiment, comprehension of stress by the same two groups was compared in tasks involving purely morphosyntactic processes. The contrastive stress patterns of otherwise homophonous compound nouns and adjectival phrases (e.g., BLACKboard, black BOARD), rather than those of pronouns, were examined. In this grammatically "simpler" experiment (i.e., without discourse-related operations), BA subjects scored significantly above chance in their comprehension of sentences involving compound nouns; unexpectedly, however, these same subjects did not show significantly above-chance performance in their comprehension of sentences containing adjectival phrases. Nevertheless, the results obtained in these two experiments seem to support the view that aphasic patients may have a lack of processing capacity, resulting in more errors during the processing of discourse-related linguistic constructions.     

Concepts are not represented by conscious imagery

According to theories of grounded cognition, conceptual representation and perception share processing mechanisms. We investigated whether this overlap is due to conscious perceptual imagery. Participants filled out questionnaires to assess the vividness of their imagery (Questionnaire on Mental Imagery) and the extent to which their imagery was object oriented and spatially oriented (Object-Spatial Imagery Questionnaire), and they performed a mental rotation task. One week later, they performed a verbal property verification task. In this task, involvement of modality-specific systems is evidenced by the modality-switch effect, the finding that performance on a target trial (e.g., apple—green) is better after a same-modality trial (e.g., diamond—sparkle) than after a different-modality trial (e.g., airplane—noisy). Results showed a modality-switch effect, but there was no systematic relation between imagery scores and modality switch. We conclude that conscious mental imagery is not fundamental to conceptual representation.     

Different standards are not double standards: all elective surgical patients are not alike

Testa and colleagues argue that evaluation for suitability for living donor surgery is rooted in paternalism in contrast with the evaluation for most operative interventions, which is rooted in the autonomy of patients. We examine two key ethical concepts that Testa and colleagues use: paternalism and autonomy, and two related ethical concepts: moral agency and shared decision making. We show that by moving the conversation from paternalism, negative autonomy, and informed consent to moral agency, relational autonomy, and shared decision making, one better understands why the arguments given by Testa and colleagues fail. We argue (1) why the hurdles that one must overcome to become a living donor are appropriate; and (2) that the similarities between living donor transplant surgery and cosmetic plastic surgery that the authors describe are inaccurate. Finally, we consider the recommendation to treat plastic surgery patients and living donors more similarly. We argue that any change should not be in the direction of becoming less protective of living donors, but more protective of cosmetic plastic surgery candidates.     

Performance bias: Why judgments of learning are not affected by learning

Past research has shown a performance bias: People expect their future performance level on a task to match their current performance level, even when there are good reasons to expect future performance to differ from current performance. One explanation of this bias is that judgments are controlled by what learners can observe, and while current performance is usually observable, changes in performance (i.e., learning or forgetting) are not. This explanation makes a prediction that we tested here: If learning becomes observable, it should begin to affect judgments. In three experiments, after practicing a skill, participants estimated how they performed in the past and how they expected to perform in the future. In Experiments 1 and 2, participants knew they had been improving, as shown by their responses, yet they did not predict that they would improve in the future. This finding was particularly striking because (a) they did improve in the future and (b) as Experiment 3 showed, they did hold the conscious belief that past improvement predicted future improvement. In short, when learning and performance are both observable, judgments of learning seem to be guided by performance and not learning.     

Why faces are and are not special: an effect of expertise

Recognition memory for faces is hampered much more by inverted presentation than is memory for any other material so far examined. The present study demonstrates that faces are not unique with regard to this vulnerability to inversion. The experiments also attempt to isolate the source of the inversion effect. In one experiment, use of stimuli (landscapes) in which spatial relations among elements are potentially important distinguishing features is shown not to guarantee a large inversion effect. Two additional experiments show that for dog experts sufficiently knowledgeable to individuate dogs of the same breed, memory for photographs of dogs of that breed is as disrupted by inversion as is face recognition. A final experiment indicates that the effect of orientation on memory for faces does not depend on inability to identify single features of these stimuli upside down. These experiments are consistent with the view that experts represent items in memory in terms of distinguishing features of a different kind than do novices. Speculations as to the type of feature used and neuropsychological and developmental implications of this accomplishment are offered.     

Ignorance reflects preference: the influence of selective ignoring on evaluative conditioning

In the current experiment, we investigated the mechanism underlying the modulation of evaluative conditioning (EC) due to selective attention. Conditioned stimulus–unconditioned stimulus (CS–US) pairs were presented in a just recently introduced adapted Flanker paradigm [Blask, K., Walther, E., & Frings, C. (2016). When congruence breeds preference: The influence of selective attention processes on evaluative conditioning. Cognition and Emotion. doi:10.1080/02699931.2016.1197100] with CSs as targets and USs as task-irrelevant distracters. In order to disentangle stimulus congruency and response compatibility and in order to observe a possible impact of response compatibility, EC in an incongruent/incompatible condition was compared to EC in an incongruent/neutral condition. Results show that EC and contingency memorywere significantly reduced in the incongruent/incompatible condition relative to the incongruent/neutral condition. These findings support the notion that the modulation of EC due to selective attention can be based on the selective ignoring of the US at the level of response compatibility.     

Going beyond the facts: Young children extend knowledge by integrating episodes

The major question posed in this research was whether 4- and 6-year-olds productively extend their knowledge by integrating information acquired in separate episodes. The vehicle was a read-aloud activity during which children were presented with a novel fact in each of two passages. In Experiment 1, both age groups showed evidence of integration between the passages. For the 6-year-olds, the evidence came in the form of responses to open-ended questions. The 4-year-olds recognized the correct answers but did not generate them in the open-ended question format. The 6-year-olds who generated the correct answers also were likely to recall both of the individual facts presented in the passages. In Experiment 2, we tested whether the 4-year-olds’ integration performance would improve if their memory for the individual facts improved. Extra exposure to the individual facts resulted in higher levels of integration performance in both recall and recognition testing. The roles of memory and other potential sources of age-related differences in integration performance are discussed.     

Predictions and causal estimations are not supported by the same associative structure

Studies performed by different researchers have shown that judgements about cue-outcome relationships are systematically influenced by the type of question used to request those judgements. It is now recognized that judgements about the strength of the causal link between a cue and an outcome are mostly determined by the cue-outcome contingency, whereas predictions of the outcome are more influenced by the probability of the outcome given the cue. Although these results make clear that those different types of judgement are mediated by some knowledge of the normative differences between causal estimations and outcome predictions, they do not speak to the underlying processes of these effects. The experiment presented here reveals an interaction between the type of question and the order of trials that challenges standard models of causal and predictive learning that are framed exclusively in associative terms or exclusively in higher order reasoning terms. However, this evidence could be easily explained by assuming the combined intervention of both types of process.     

The neurology of syntax: language use without Broca's area

A new view of the functional role of the left anterior cortex in language use is proposed. The experimental record indicates that most human linguistic abilities are not localized in this region. In particular, most of syntax (long thought to be there) is not located in Broca's area and its vicinity (operculum, insula, and subjacent white matter). This cerebral region, implicated in Broca's aphasia, does have a role in syntactic processing, but a highly specific one: It is the neural home to receptive mechanisms involved in the computation of the relation between transformationally moved phrasal constituents and their extraction sites (in line with the Trace-Deletion Hypothesis). It is also involved in the construction of higher parts of the syntactic tree in speech production. By contrast, basic combinatorial capacities necessary for language processing--for example, structure-building operations, lexical insertion--are not supported by the neural tissue of this cerebral region, nor is lexical or combinatorial semantics. The dense body of empirical evidence supporting this restrictive view comes mainly from several angles on lesion studies of syntax in agrammatic Broca's aphasia. Five empirical arguments are presented: experiments in sentence comprehension, cross-linguistic considerations (where aphasia findings from several language types are pooled and scrutinized comparatively), grammaticality and plausibility judgments, real-time processing of complex sentences, and rehabilitation. Also discussed are recent results from functional neuroimaging and from structured observations on speech production of Broca's aphasics. Syntactic abilities are nonetheless distinct from other cognitive skills and are represented entirely and exclusively in the left cerebral hemisphere. Although more widespread in the left hemisphere than previously thought, they are clearly distinct from other human combinatorial and intellectual abilities. The neurological record (based on functional imaging, split-brain and right-hemisphere-damaged patients, as well as patients suffering from a breakdown of mathematical skills) indicates that language is a distinct, modularly organized neurological entity. Combinatorial aspects of the language faculty reside in the human left cerebral hemisphere, but only the transformational component (or algorithms that implement it in use) is located in and around Broca's area.