SimDialog: A visual game dialog editor

SimDialog is a visual editor for dialog in computer games. This paper presents the design of SimDialog, illustrating how script writers and non-programmers can easily create dialog for video games with complex branching structures and dynamic response characteristics. The system creates dialog as a directed graph. This allows for play using the dialog with a state-based cause and effect system that controls selection of non-player character responses and can provide a basic scoring mechanism for games

The Implicit Learning of Base-rates: Evidence from Working Memory Disruption

Base-rates, or relative prevalence in the environment, play an important role in many diagnostic and categorical decisions. For example, in order for a doctor to make an appropriate diagnosis or treatment plan, he/she must be sensitive to the underlying base-rates. Early base-rate research seemed to show that people were insensitive to base-rates and poor at incorporating them into their judgments (e.g., Kahneman & Tverksy, 1973). However, more recent research has shown that people are sensitive to base-rates when they are learned through direct experience rather than presented in summary form (e.g., Bohil & Maddox, 2001; Estes, 1989). Using a category learning approach, the current study sought an explanation for experience-based sensitivity to base-rates through the lens of COVIS theory – a prominent multiple-systems approach to category learning. COVIS postulates that there are separate implicit and explicit systems involved in category learning. Implicit (nonverbalizable) learning is aided by the dopamine release involved in a motor response with immediate feedback while explicit learning relies heavily on working memory for hypothesis testing and verbalizable rule generation. A recent study found that disrupting the implicit learning system during categorization with unequal base-rates led to a weaker influence of base-rates on decision criterion (signal detection b) placement (Bohil & Wismer, 2014). The current study attempted to corroborate these findings by investigating whether the addition of a verbal working memory task immediately after category feedback (disrupting explicit reasoning about category feedback) would affect the influence of base-rates on categorization. In this study, 123 participants completed one of four conditions (observational/response training x short/long feedback processing time). Participants first learned two simple perceptual categories with equal base-rates. After achieving a pre-determined accuracy criterion, participants moved on to the experimental phase with unequal base-rates (3:1) and the inclusion of a verbal working memory task presented either immediately after receiving category feedback (500ms) or after a delay (2500ms). The experimental phase consisted of alternating training blocks (with feedback) and test blocks (without feedback). Half the participants learned observationally during training phases (known to disrupt implicit learning) while half made a classification response during training trials (which supports implicit learning). As predicted, we found that disrupting working memory had no effect on the influence of base-rates on categorization when implicit learning was possible (in terms of decision criterion values determined by signal detection and decision-bound modeling results). Our results support the multiple-systems theory which predicts that disrupting working memory should not affect base-rate sensitivity if sensitivity to base-rates is indeed mediated by the implicit learning system. These findings have implications for devising appropriate training methods for diagnosticians in various fields

Cognitive Modeling of Video Game Player User Experience

This paper argues for the use of cognitive modeling to gain a detailed and dynamic look into user experience during game play. Applying cognitive models to game play data can help researchers understand a player's attentional focus, memory status, learning state, and decision strategies (among other things) as these cognitive processes occurred throughout game play. This is a stark contrast to the common approach of trying to assess the long-term impact of games on cognitive functioning after game play has ended. We describe what cognitive models are, what they can be used for and how game researchers could benefit by adopting these methods. We also provide details of a single model - based on decision field theory - that has been successfUlly applied to data sets from memory, perception, and decision making experiments, and has recently found application in real world scenarios. We examine possibilities for applying this model to game-play data

Myosin-X is a molecular motor central to filopodia formation, adhesion, and signaling

Understanding cellular and molecular components of cell migration is critical to the advancement of normal physiology and cancer biology. There is growing realization that finger-like cellular protrusions called filopodia play central roles in the cell biology underlying angiogenesis and inflammation (Anderson and Anderson, 1976; Gerhardt et al., 2003). Despite this knowledge, very little is known about the fundamental mechanisms governing filopodia formation, signaling, and adhesion. Unconventional myosins, particularly the MyTH4-FERM class of myosins, are implicated in precisely these types of filopodial functions (Tuxworth et al., 2001). Myosin-X (Myo10) is a vertebrate-specific member of the MyTH4-FERM class of myosins that is expressed in most cells and tissues. When expressed in cells, GFP-Myo10 displays a striking localization to tips of filopodia and undergoes intrafilopodial motility (Berg and Cheney, 2002). The experiments described in this dissertation demonstrate that Myo10 is a component of a putative filopodial tip complex, that it binds integrins (Zhang et al., 2004), and that it is a potent inducer of dorsal filopodia (Bohil et al., 2006)

The psychological interaction of spam email features

This study explored distinct perceptual and decisional contributions to spam email mental construal. Participants classified spam emails according to pairings of three stimulus features – presence or absence of awkward prose, abnormal message structure, and implausible premise. We examined dimensional interactions within general recognition theory (GRT; a multidimensional extension of signal detection theory). Classification accuracy was highest for categories containing either two non-normal dimension levels (e.g. awkward prose and implausible premise) or two normal dimension levels (e.g. normal prose and plausible premise). Modelling indicated both perceptual and decisional contributions to classification responding. In most cases, perceptual discriminability was higher along one dimension when stimuli contained a non-normal level of the paired dimension (e.g. prose discriminability was higher with abnormal structure). Similarly, decision criteria along one dimension were biased in favour of the non-normal response when stimuli contained a non-normal level of the paired dimension. Potential applications for training are discussed

Myosin-X is a molecular motor that functions in filopodia formation

Despite recent progress in understanding lamellipodia extension, the molecular mechanisms regulating filopodia formation remain largely unknown. Myo10 is a MyTH4-FERM myosin that localizes to the tips of filopodia and is hypothesized to function in filopodia formation. To determine whether endogenous Myo10 is required for filopodia formation, we have used scanning EM to assay the numerous filopodia normally present on the dorsal surfaces of HeLa cells. We show here that siRNA-mediated knockdown of Myo10 in HeLa cells leads to a dramatic loss of dorsal filopodia. Overexpressing the coiled coil region from Myo10 as a dominant- negative also leads to a loss of dorsal filopodia, thus providing independent evidence that Myo10 functions in filopodia formation. We also show that expressing Myo10 in COS-7 cells, a cell line that normally lacks dorsal filopodia, leads to a massive induction of dorsal filopodia. Because the dorsal filopodia induced by Myo10 are not attached to the substrate, Myo10 can promote filopodia by a mechanism that is independent of substrate attachment. Consistent with this observation, a Myo10 construct that lacks the FERM domain, the region that binds to integrin, retains the ability to induce dorsal filopodia. Deletion of the MyTH4-FERM region, however, completely abolishes Myo10's filopodia-promoting activity, as does deletion of the motor domain. Additional experiments on the mechanism of Myo10 action indicate that it acts downstream of Cdc42 and can promote filopodia in the absence of VASP proteins. Together, these data demonstrate that Myo10 is a molecular motor that functions in filopodia formation

Sequential roles for myosin-X in BMP6-dependent filopodial extension, migration, and activation of BMP receptors

Endothelial cell migration is an important step during angiogenesis, and its dysregulation contributes to aberrant neovascularization. The bone morphogenetic proteins (BMPs) are potent stimulators of cell migration and angiogenesis. Using microarray analyses, we find that myosin-X (Myo10) is a BMP target gene. In endothelial cells, BMP6-induced Myo10 localizes in filopodia, and BMP-dependent filopodial assembly decreases when Myo10 expression is reduced. Likewise, cellular alignment and directional migration induced by BMP6 are Myo10 dependent. Surprisingly, we find that Myo10 and BMP6 receptor ALK6 colocalize in a BMP6-dependent fashion. ALK6 translocates into filopodia after BMP6 stimulation, and both ALK6 and Myo10 possess intrafilopodial motility. Additionally, Myo10 is required for BMP6-dependent Smad activation, indicating that in addition to its function in filopodial assembly, Myo10 also participates in a requisite amplification loop for BMP signaling. Our data indicate that Myo10 is required to guide endothelial migration toward BMP6 gradients via the regulation of filopodial function and amplification of BMP signals

Cognitive loading affects motor awareness and movement kinematics but not locomotor trajectories during goal-directed walking in a virtual reality environment.

The primary purpose of this study was to investigate the effects of cognitive loading on movement kinematics and trajectory formation during goal-directed walking in a virtual reality (VR) environment. The secondary objective was to measure how participants corrected their trajectories for perturbed feedback and how participants' awareness of such perturbations changed under cognitive loading. We asked 14 healthy young adults to walk towards four different target locations in a VR environment while their movements were tracked and played back in real-time on a large projection screen. In 75% of all trials we introduced angular deviations of ±5° to ±30° between the veridical walking trajectory and the visual feedback. Participants performed a second experimental block under cognitive load (serial-7 subtraction, counter-balanced across participants). We measured walking kinematics (joint-angles, velocity profiles) and motor performance (end-point-compensation, trajectory-deviations). Motor awareness was determined by asking participants to rate the veracity of the feedback after every trial. In-line with previous findings in natural settings, participants displayed stereotypical walking trajectories in a VR environment. Our results extend these findings as they demonstrate that taxing cognitive resources did not affect trajectory formation and deviations although it interfered with the participants' movement kinematics, in particular walking velocity. Additionally, we report that motor awareness was selectively impaired by the secondary task in trials with high perceptual uncertainty. Compared with data on eye and arm movements our findings lend support to the hypothesis that the central nervous system (CNS) uses common mechanisms to govern goal-directed movements, including locomotion. We discuss our results with respect to the use of VR methods in gait control and rehabilitation