< June, 2013 >
In the focus of the eCIRCUS project is emotion and its role in social learning: social and emotional learning is to take place when children interact with educational agents that inhabit virtual realities. To provide this social and emotional learning in children, the agents need to feature emotions, as well as emotional expression, in order for the user to connect socially to these agents.
Hence, modelling emotion in agents is key to enable social learning processes is users that interact with in educational software agents as they are going to be provided by the eCIRCUS project; emotions need to be reasonably integrated in the agent architecture. Within the eCIRCUS project, several approaches to modelling agents are researched:
OCC model of emotions (Ortony, Clore & Collins, 1988; Dias, 2005)
This concept of emotions is used to model emotions in the FearNot! software. It defines emotions as valenced reactions to events that are assessed by a character regarding its goals, standards and attitudes (appraisal). These appraisals result in emotions: a character perceives an event it the environment, relates it to its goals, standards, and attitudes, and as a result, experiences an emotion. All in all, 22 emotions are modelled, which are hierarchically grouped in categories. These are:
» Well Being Emotions are triggered when the character perceives a desirable or undesirable event (e.g. joy, fear).
» Attraction Emotions are generated by the presence of other characters or objects based on appraisals of the characters’ attitudes (e.g. like, dislike).
» Attribution Emotions result from appraisals of (other) characters’ actions regarding social or moral standards (e.g. pride, shame, admiration, and reproach).
» Fortune of Others Emotions stem from the appraisal of the desirability of an event for others (e.g. gloating).
» Prospect based Emotions occur due to an appraisal of consequences of events according to the characters’ goals (if the prospect is unconfirmed: hope, fear; if the prospect is confirmed: satisfaction, relief).
Additional to the type of emotion, other information is activated when an emotion is experienced by an agent: the valence of the emotion (positive, negative), its direction (name of object or character the emotion is targeted to), its cause (event or action that caused the emotion), intensity of the emotion, and time stamp (beginning and updating of the emotion).
To model the fact that emotions change over time, decay rates specify how long an emotion is active. Several emotions can be active simultaneously.
Arousal is modelled by assuming that the general intensity of emotions felt by the character increases its arousal level. In contrast, arousal decreases with time if nothing happens. Mood represents the overall valence of a character’s emotional state: it is thus deduced from emotions depending on their valence and intensity. On the other hand, it also influences emotions in that it heightens the probability of experiencing positive emotions when it is positively toned, and it heightens the probability of experiencing negative emotions when it is negatively toned.
Emotions and Action In FearNot!, emotions are generated and updated whenever a goal leads to an intention. Also, planning may generate emotions, for example hope, fear, satisfaction, relief, or disappointment. On the other hand, emotions influence the selection of intentions as well as the persistence of clinging to a plan.
Emotions in the PSI model (Dörner, 1998)
The PSI theory represents a general psychological approach to model the human psyche. It is global as far as it covers emotional, cognitive, motivational, and behavioural aspects. It deals with both deliberate action and automatic behaviour, and conceptualises emotion not as a separate module within the human psyche but as a mode in which the psychic apparatus works.
Action Regulation According to the PSI-theory, the basic units of the psychological apparatus are sensory and motor schemes (Schaub, 2001) that are stored in memory. Sensory schemes serve perception and motor schemes serve action. Sensory schemes represent what the character knows about the world and thus what it can perceive. Actions that the character can perform are represented by motor schemes. Motor schemes are organized hierarchically and represent the link between intentions and action.
But what is an intention? All human behaviour is based on the satisfaction of basic needs, which can be reduced to fives basic classes of needs according to the PSI theory:
existence conserving needs
hunger, thirst, avoiding pain,…
need for sexuality
to conserve the species
the need for social interaction
need for certainty
the organism seeks to know his environment and to be able to predict what will happen
need for competence
the organism seeks to be competent and to be able to solve the tasks of everyday life
The stronger the need the more probable an action that is appropriate to satisfy the need: For example, if one is thirsty, drinking is more probable than if one is not thirsty. But the strength of need is not the only criterion that leads to the selection of an action: success probability and urgency are also important. These three concepts form the intention to satisfy a need; as more than one need can be active at any given moment several needs compete to trigger an action. Finally, the strongest intention will lead to action. As mentioned above, this is done by activating hierarchically organised motor schemes.
Emotional Modulation Emotion is –represented by three so-called “emotional parameters” that modulate cognitive processes and constitute an emotion as experienced by the character:
preparedness for perception and reaction on side of the organism
accuracy with which the organism perceives his environment
Concentration on the execution of the actual intention (low = easy to be distracted from executing current intention)
The parameters are interrelated: activation effects resolution level and selection threshold, and activation is directly linked to the satisfaction of needs. For example, if the character is moderately activated (needs are rather satisfied), resolution is high and selection threshold is rather low. The character would be in a rather good, relaxed mood, enjoying the situation and being rather easily distracted. But in case needs suddenly rise, e.g. because something unexpected happens (need for certainty rises), the character’s activation will also rise, resolution level decreases (the character focuses on few important aspects of the unexpected event rather than scanning the whole situation in detail), and selection threshold rises, too (concentration on understanding the unexpected event). The character is surprised, if it continually fails to categorise what is happening, it becomes fearful, as need for certainty remains high and need for competence rises as well, since the character realises the it is unable to satisfy its needs.
To sum up, emotions within the PSI theory are conceptualised as specific modulations of cognitive and motivational processes. These modulations are realised by so called emotional parameters. Different combinations of parameter values result in the subjective experience of emotion.
Active intentions are ideally handled when activation is moderate, selection threshold and resolution level are high (concentration, accuracy). Depending on the cognitive resources and the motivational state of the organism in a given situation, these parameters are adjusted, resulting in more or less careful or forceful ways of acting, as well as more or less deliberate cognitive processing.
Created on 01/23/2007 11:10 AM by ecirweb
Updated on 01/23/2007 11:24 AM by ecirweb