Table 1: Neurocognitive approaches to study anticipation.

Methodology	Description	Pros/ Cons	Examples of Clinical Implementation
Self-report Questionnaires	Self-report scales typically include items that inquire about an individual’s expectations, excitement, and motivation in response to potential rewards (Figure 2A). Classic metrics are mostly focused on consummatory pleasure, while second generation scales are designed to target anticipatory and consummatory pleasure separately (e.g. Temporal Experience of Pleasure, TEPS). Anticipation of negative experiences is in general less explored in self-report scales, with some exceptions focusing on anxiety by generated by future aversive events. Other relevant instruments have focused on attitudes towards uncertainty	Self-reports questionnaires are easy administer and can offer insights about individual anticipatory traits across psychiatric disorders, such as schizophrenia and eating disorders. Inconsistent findings and difficulty to delineate anticipatory vs. consummatory pleasure solely from questionnaires, since reporting consummatory pleasure demands various additional cognitive functions, such as imagination and memory.	Temporal Experience of Pleasure Scale (TEPS) in schizophrenia has indicated specific deficits to anticipatory pleasure processing. Intolerance to Uncertainty questionnaires administered in various psychiatric conditions, including generalized anxiety disorder OCD, and depression.
Behavioral tasks
Monetary Incentive Delay Task (MID)	Neuroimaging based paradigm, where participants receive a cue signaling that they will receive a monetary reward if they successfully press a button in response to a second cue displayed after a few seconds (Figure 2B). Functional magnetic resonance imaging (fMRI) response to the first reward-predictive cue is often considered a neural correlate of reward anticipation, for which regions in the mesolimbic dopamine circuit, including the ventral striatum and ventral tegmental area, as well as anterior cingulate are reliably implicated.	One of the most robust and influential approaches to measure anticipatory signals at a neural level. MID paradigm uses as the primary behavioral measure participant’s reaction time, which is unclear how it is associated with altered anticipation. Attention and sensory-motor processing could also affect the reaction time. The typical anticipatory period of the MID paradigm (a few seconds) makes it challenging to dissociate phasic prediction error from slow reward anticipation. Such a delineation may require a task with longer anticipatory periods and computational models that make quantitative predictions about anticipatory processes.	Individuals with schizophrenia show blunted responses in the ventral striatum compared to healthy volunteers. Individuals with major depressive disorders show larger anterior cingulate cortex response and similar or smaller ventral striatal response than healthy volunteers but the alteration can be normalized by selective serotonin reuptake inhibitor (SSRI) treatment.
Neutral Predictable Uncertain (NPU) Threat	Developed based on classical conditioning, the NPU threat test examines potentially distinct responses to predictable and unpredictable threats (Figure 2C). In this paradigm, fear is associated with a fast and transient response to discrete and certain aversive stimuli, whereas anxiety is associated with sustained emotional response to unpredictable stimuli. Fear and anxiety are assessed using the startle reflex, a measure of aversive state elicited by the unpleasant stimuli, e.g. electric shocks.	The startle is a cross-species metric extendedly used in experiments that can be implemented multiple populations, facilitating translational research. A limitation is the gap between the simple startle responses, or eye blinks, and complex cognitive behaviors manifested in psychiatric conditions, such as decision making.	Individuals with panic disorder and post-traumatic stress disorder present greater startle responses to unpredictable, but not predictable, aversive experiences relative to healthy volunteers. Inhibited startle response to unpredictable events has been associated with avoidance strategies and intolerance of uncertainty.