The present thesis aims to elucidate the contribution of various regions within the posterior parietal cortex (PPC) to reading and to writing. The first study uses functional magnetic resonance imaging to examine writing-related activity in various parts of the PPC. The results indicate that, during writing, the anterior aspect of the superior parietal lobule (cytoarchitectonic area PE) is involved. A correlated increase in activation occurs between area PE and the anterior region of the supramarginal gyrus when writing is in response to a pictured object. In contrast, when writing is in response to a word that has just been read, a correlated increase in activation occurs between area PE and the angular gyrus region. The first study, therefore, dissociates the contributions of the superior parietal lobule, the supramarginal gyrus, and the angular gyrus to reading and writing. In order to examine with greater precision where within the larger angular gyrus region the focal peaks of activation during reading occur, it was necessary to characterize the anatomy of the angular gyrus region in more precise terms. The classical definition of the angular gyrus (the cortex surrounding the caudal part of the superior temporal sulcus) is a rather loose definition. The second study provides a detailed description of the gross morphology of the region of the angular gyrus, based on structural magnetic resonance images of 45 human brains. The results demonstrate that there are three caudal branches of the superior temporal sulcus that ascend into the inferior parietal lobule and that constitute the angular gyrus (cSTS1, cSTS2, cSTS3). The third study, drawing heavily on the findings from the second study, investigates functional activation during reading in relation to the caudal branches of the superior temporal sulcus. The results suggest that reading-related activation falls between the second (cSTS2) and third (cSTS3) branches of the caudal superior temporal sulcus (cytoarchitectonic area PG). It is suggested that area PG supports reading because it is part of the dorsal processing stream that supports spatial cognition and that reading involves visuo-spatial processing. Taken together, the data from all three studies presented in the present thesis not only confirm the involvement of the PPC in reading and in writing, but also dissociate the contributions of various regions within this large and heterogeneous part of the human brain to reading and writing processes, thereby advancing our understanding of the contribution of the PPC to reading and writing. / Le but de ces études était de déterminer la contribution des différentes subdivisions du cortex pariétal postérieur dans l'écriture et la lecture. La première étude examine, grâce à l'imagerie par résonance magnétique fonctionnelle, les activités observées pendant l'écriture dans des conditions variées. Les résultats montrent que la région antérieure du lobule pariétal postérieur (l'aire cytoarchitectonique PE) est impliquée dans l'écriture. Il existe une corrélation entre l'augmentation d'activité dans l'aire PE et dans la partie antérieure du gyrus supramarginal quand l'écriture est produite à la présentation de la photo d'un objet. Par contre, quand l'écriture est produite en réponse à un mot qui vient d'être lu, il existe une corrélation entre l'augmentation d'activité observée dans l'aire PE et la région du gyrus angulaire. Cette première étude montre une dissociation entre les contributions respectives du lobule pariétal supérieur, du gyrus supramarginal, et du gyrus angulaire dans l'écriture et la lecture. La caractérisation de l'anatomie de la région du gyrus angulaire dans des termes plus précis est fondamentale pour examiner avec précision la localisation des activités observées lors de la lecture. La définition du gyrus angulaire (la région corticale localisée autour de la partie caudale du sillon temporal supérieur) reste largement imprécise pour une région corticale complexe. La seconde étude vise à décrire en détail la morphologie de la région du gyrus angulaire sur la base d'images structurelles obtenues chez 45 sujets humains sains grâce à l'imagerie par résonance magnétique. Les résultats démontrent que, caudalement, trois branches émergent du sillon temporal supérieur et remontent dans le lobule pariétal inférieur, constituant le gyrus angulaire (cSTS1, cSTS2, cSTS3).La troisième étude, basée sur les résultats obtenus dans la seconde étude, vise à déterminer les relations entre les branches caudales du sillon temporal supérieur et les activités observées pendant l'écriture et la lecture. Les résultats suggèrent que l'activité observée pendant la lecture est localisée entre la seconde (cSTS2) et la troisième branche (cSTS3) du sillon temporal supérieur caudal, (l'aire cytoarchitectonique PG). L'aire PG fait partie de la voie dorsale de traitement visuel et la cognition visuo-spatiale, et a été suggérée comme impliquée dans la lecture parce-que l'analyse visuo-spatiale est un aspect fondamental de la lecture. L'ensemble des données présentées dans cette thèse confirment l'implication cruciale du cortex pariétal postérieur dans l'écriture et la lecture et démontrent une dissociation entre les contributions des différentes subdivisions de cette région dans ces processus. Cette thèse permet des avancées significatives dans notre compréhension de la contribution du cortex pariétal postérieur dans l'écriture et la lecture.

<p> Currently there is disagreement on the best tools for measuring situation awareness (SA) as well as the nature of the processes that underlie it. The current project examined the intrusiveness of two commonly used techniques, the Situation Awareness Global Assessment Technique (SAGAT) and the Situation Present Assessment Method (SPAM), on operator SA, workload, and performance by manipulating the key features distinguishing the techniques&mdash;whether displays remain visible and whether scenarios are paused. The results indicated that both factors affect operator SA, workload, and performance. We also found that the intrusiveness associated with blanking displays and not pausing scenarios depended on the type of information being queried. Specifically, making information more difficult to access from external displays had a more negative effect on the ability to answer queries pertaining to specific aircraft as opposed to general sector characteristics. These results support the Situated SA approach, which holds that operators often off-load information to their environment to limit what they must store internally.</p>

<p> This hermeneutical case study looked at human conflict and human difference at the scale of local political life in democratically elected public bodies, using the lens of embodied mind and congruent phenomenological research approaches to examine whether facets could be added to the display of Varela's (1996) proposed experiential phenomenological structures. In particular, the study focused on the pre-reflective moments of intersubjective interaction between people seeking different goals. It then considered the interplay between the perceptions received during those pre-reflective moments of experienced difference with post-reflective conceptions created as a result of the encounters. In doing so, the study found evidence in support of Varela's (1996) suggested structural invariants of experience. In particular, through the use of the elicitation techniques as described by Petitmengin-Peugeot (1999) and Vermersch (2009), participants in differing setting and facts experienced common structural invariants of difference. Those structures were preceded by intention and evidenced by strong affective cues which arose during encounters and which lead to structures of felt resistance, oppositional defiance and the experience of emotional feelings.</p>

<p> In many complex and dynamic domains, the ability to generate and then select the appropriate course of action is based on the decision maker's "reading" of the situation--in other words, their ability to assess the situation and predict how it will evolve over the next few seconds. Current theories regarding option generation during the situation assessment and response phases of decision making offer contrasting views on the cognitive mechanisms that support superior performance. The Recognition-Primed Decision-making model (RPD; Klein, 1989) and Take-The-First heuristic (TTF; Johnson &amp; Raab, 2003) suggest that superior decisions are made by generating few options, and then selecting the first option as the final one. Long-Term Working Memory theory (LTWM; Ericsson &amp; Kintsch, 1995), on the other hand, posits that skilled decision makers construct rich, detailed situation models, and that as a result, skilled performers should have the ability to generate more of the available task-relevant options. </p><p> The main goal of this dissertation was to use these theories about option generation as a way to further the understanding of how police officers anticipate a perpetrator's actions, and make decisions about how to respond, during dynamic law enforcement situations. An additional goal was to gather information that can be used, in the future, to design training based on the anticipation skills, decision strategies, and processes of experienced officers. Two studies were conducted to achieve these goals. </p><p> Study 1 identified video-based law enforcement scenarios that could be used to discriminate between experienced and less-experienced police officers, in terms of their ability to anticipate the outcome. The discriminating scenarios were used as the stimuli in Study 2; 23 experienced and 26 less-experienced police officers observed temporally-occluded versions of the scenarios, and then completed assessment and response option-generation tasks. </p><p> The results provided mixed support for the nature of option generation in these situations. Consistent with RPD and TTF, participants typically selected the first-generated option as their final one, and did so during both the assessment and response phases of decision making. Consistent with LTWM theory, participants--regardless of experience level--generated more task-relevant assessment options than task-irrelevant options. However, an expected interaction between experience level and option-relevance was not observed. </p><p> Collectively, the two studies provide a deeper understanding of how police officers make decisions in dynamic situations. The methods developed and employed in the studies can be used to investigate anticipation and decision making in other critical domains (e.g., nursing, military). The results are discussed in relation to how they can inform future studies of option-generation performance, and how they could be applied to develop training for law enforcement officers. </p>

Most research studies on crossmodal processing of visual and tactile modalities have found that vision enhances touch. Nevertheless, it is unclear whether vision increases tactile sensitivity or changes participants' response criteria for reporting touch. The following set of studies demonstrated that some experimental manipulations can lead to a small increase in tactile sensitivity; however, all experiments showed a consistently strong response bias to report feeling a touch with a concomitant visual stimulus. Further experiments sequenced the temporal processes associated with the visuotactile response bias and determined that greater visual influences on electrotactile processing occurred at smaller crossmodal asynchronies. A final experiment demonstrated that the reported electrotactile enhancement bias on light-present trials can be increased with transcranial magnetic stimulation (TMS) over the posterior parietal cortex 200 ms after visual and electrotactile stimuli presentation. Further research needs to be conducted to determine more precise cortical locations and temporal sequences of the crossmodal interactions between vision and touch.

The impact of the physical design elements on the effectiveness of warning labels has been well researched over the past few decades. This research extends warning design research by applying a value-expectancy model to safety decision-making (DeJoy, 1999a) by explicitly examining how a well-designed warning label impacts perceptions of the costs and benefits, or expected value, of using a product. This problem is examined within the context of over-the-counter dietary supplements used to lose weight---a product with perceived value in certain groups and with two potential cost-benefit analyses associated with it (using the pills and seeing a doctor first). First, a qualitative study was conducted in order to determine what consumers and potential consumers know about the safety of dietary supplements. Further, Study 1 (n = 25) gathered information regarding what costs and benefits participants (may) consider when deciding whether or not to use diet pills and when deciding whether or not to see a physician before using the pills. The Study 1 findings were used to craft two warning labels that were used in Study 2 ( n = 174). The warning labels were either framed to highlight consequences of each hazard presented or were framed to be more neutral and only present hazard information, leaving the participant to infer consequences. Interestingly, although the consequence label increased expected compliance, in accord with past research (e.g. Laughery, Vaubel, Young, Brelsford, and Rowe, 1993), the consequence label only significantly increased the perceived costs associated with the precautionary action (i.e. visiting a doctor before using) and not with using the pills. These results, along with the findings relevant to individual differences, may help to identify instances where well-designed warnings do not always yield compliance in the field. That is, though warning labels may be impact participant perceptions of expected compliance, they may not impact perceptions of the precautionary action in expected ways.

Two nonfluent aphasic patients, ML and AR, and two fluent aphasic patients, LC and LW, along with older controls were tested on tasks involving semantic blocking and lexical selection. In Experiment 1, a repeated picture-naming task manipulating semantic blocking and presentation rate, both nonfluent patients showed growing semantic interference across trials, while the other subjects did not. In Experiment 2, a corresponding comprehension task, ML showed increasing semantic interference while AR showed a lack of repetition priming. Experiment 3 was a category fluency task in which AR performed very poorly and ML performed similarly to the fluent patients. Experiment 4 was a sentence completion task, and no evidence was found that the number or relatedness of lexical competitors caused any difficulty for the nonfluent patients. It was concluded that ML suffers from deficient semantic inhibitory mechanism while AR suffers from an under-activation of lexical representations.

The following series of experiments examined whether common mechanisms are involved in word retrieval within language and memory domains. Four patients with short-term memory (STM) deficits were examined; however, two of the patients showed a consistent impairment in inhibiting irrelevant verbal information as well. To the extent that repeatedly retrieving verbal items from the same category would require the capacity to suppress competing items to select the target, we investigated whether patients with a verbal inhibitory deficit, in addition to a reduced STM capacity, would be impaired in retrieving items in a semantic context relative to STM patients who do not display a similar verbal inhibition deficit and normal control subjects. Experiments 1- 4 consisted of language tasks which required the repeated naming or matching of items in a semantic or unrelated context. The findings revealed that verbal inhibition patients showed the greatest degree of difficulty during picture naming relative to the matching tasks in a semantic context, suggesting that they are susceptible to interference from semantic competitors to a greater extent at a lexical level. Experiments 5 - 7 consisted of recall and recognition memory tasks with items in a semantically related or unrelated context. Experiments 5 and 6 showed that while STM patients and controls displayed a similar degree of interference for items in a semantic context, STM patients can recall and recognize items near or within the range of controls when demands on STM capacity are minimal during encoding. However, Experiment 7 showed that recall can decline for patients with STM deficits when items are processed more rapidly during encoding. The results from Experiments 5 - 7 suggest that interference among items from the same category can occur in memory tasks (at a conceptual level), but verbal inhibition patients are not affected to a greater degree than control subjects. The overall findings are interpreted within the framework of spreading activation models, and provide implications for potential differences in competition and selection demands at lexical and conceptual levels of representation.

Much research has shown that information outside of awareness can be processed to some degree. Here we used overlapping pictures and words presented in a RSVP paradigm to examine the effect of semantic congruency in an unattended dimension on performance in an attended dimension. We hypothesized that if unattended information is processed, then by manipulating the congruency of the dimensions we may see facilitory or inhibitory effects on subject's responses to attended items. We found that when an unattended congruent word preceded a picture target by a lag of 2 items or 4 items, responses to that target picture were speeded compared to when the word was unrelated to the target. This finding suggests that the unattended information is being processed to the level at which it can influence behavior and that this processing lasts for an extended duration after the item is presented.

Implicit learning, defined here as learning without intention, was demonstrated during the performance of a search task, thereby extending the finding of implicit learning in relatively simple tasks. Implicit learning was primarily limited to unique associations in a target feature sequence (i.e., associations in which a particular element is always followed by the same element, as 2 follows 1 in the sequence 125124). Implicit learning was similar under both distributed and focused visual attention and was unaffected by added workload, indicating that implicit learning utilized minimal attentional resources. In contrast, when subjects were instructed to learn the sequence (i.e., were to use an explicit learning mode), sequence learning was adversely affected by added workload, and the impairment was similar for both unique and ambiguous associations. Implicit learning in a distributed-attention search task was similar to implicit learning in a simpler serial reaction time task. However, in a focused-attention search task that was more perceptually-demanding, sequence learning benefits did not appear until late in task performance. This pattern suggests that implicitly-learned sequence information may have been retrieved and used only after becoming explicit. This research also demonstrated that associations between sequence elements are not learned implicitly if a sequenced stimulus feature is not assigned to responses. This indicates that associations between stimulus-response pairs, but not between stimuli alone, were learned. In addition to ambiguous sequence associations, high perceptual demands, and the absence of response assignments for patterned stimuli, low accuracy rates, low event rates, and cumbersome response codes were implicated as potential sources of interference in implicit learning. An instance-based model of implicit learning is indirectly supported, according to which implicit learning benefits reflect the storage and subsequent activation (i.e., retrieval) of instances that contain response-relevant stimulus information, the response, and information about the next event or immediate consequence of that response.