From 76ce186748759978fddb82a6eedbb727ba59b857 Mon Sep 17 00:00:00 2001
From: Constantinos Eleftheriou <constantinos.eleftheriou@ed.ac.uk>
Date: Tue, 29 Sep 2026 15:33:01 +0100
Subject: [PATCH 1/3] fix response alignment issue

---
 src/mesoscopy/process/perievent.py | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/src/mesoscopy/process/perievent.py b/src/mesoscopy/process/perievent.py
index 9df415c..50fc6c5 100644
--- a/src/mesoscopy/process/perievent.py
+++ b/src/mesoscopy/process/perievent.py
@@ -61,7 +61,7 @@ def event_times(trials: pd.DataFrame, event: str) -> tuple[npt.NDArray[np.float6
     Args:
         trials (pd.DataFrame): Trials table as written by `visiomode-analysis session`, with `start_time`,
             `cue_onset`, `stop_time`, `response_time` and `sdt_type` columns. Times are seconds from
-            behaviour start.
+            behaviour start, except `response_time`, which is seconds from `cue_onset`.
         event (str): One of `cue_onset`, `trial_start`, `response` or `reward`.
 
     Returns:
@@ -80,8 +80,9 @@ def event_times(trials: pd.DataFrame, event: str) -> tuple[npt.NDArray[np.float6
     elif event == "response":
         import pandas as pd
 
+        # `response_time` is measured from the cue.
         response_time = pd.to_numeric(trials["response_time"], errors="coerce").to_numpy(dtype=np.float64)
-        times = trials["start_time"].to_numpy(dtype=np.float64) + response_time
+        times = trials["cue_onset"].to_numpy(dtype=np.float64) + response_time
         keep = ~np.isnan(response_time) & (response_time >= 0) & ~np.isnan(times)
     elif event == "reward":
         times = trials["stop_time"].to_numpy(dtype=np.float64)

From b0539d4e873842419a1a5cbd1406c62aedab7662 Mon Sep 17 00:00:00 2001
From: Constantinos Eleftheriou <constantinos.eleftheriou@ed.ac.uk>
Date: Tue, 29 Sep 2026 15:33:15 +0100
Subject: [PATCH 2/3] add expected response event times

---
 tests/test_process.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tests/test_process.py b/tests/test_process.py
index cc88833..dd1a0a8 100644
--- a/tests/test_process.py
+++ b/tests/test_process.py
@@ -1820,7 +1820,7 @@ class TestEventTimes:
         [
             ("cue_onset", [1.0, 5.5, 10.5, 15.5, 20.5, 40.5], [0, 1, 2, 3, 4, 5]),
             ("trial_start", [0.5, 5.0, 10.0, 15.0, 20.0, 40.0], [0, 1, 2, 3, 4, 5]),
-            ("response", [1.2, 6.2, 20.8, 40.5], [0, 1, 4, 5]),
+            ("response", [1.7, 6.7, 21.3, 41.0], [0, 1, 4, 5]),
             ("reward", [3.0, 8.0, 23.0, 41.5], [0, 1, 4, 5]),
         ],
     )

From 757d5a99c257cf4ff58716081b6128604f1fbcbd Mon Sep 17 00:00:00 2001
From: Constantinos Eleftheriou <constantinos.eleftheriou@ed.ac.uk>
Date: Tue, 29 Sep 2026 15:33:23 +0100
Subject: [PATCH 3/3] update changelog entry

---
 CHANGELOG.md | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 729c07b..52bda8e 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -4,6 +4,10 @@ Versions follow [Semantic Versioning](https://semver.org) (`<major>.<minor>.<pat
 
 ## Unreleased
 
+### Fixed
+
+- `process peri-event --event response` wrongly aligned windows to `start_time + response_time`, which falls before the cue since `response_time` is measured from the cue and every trial starts with the ITI. The lever push is now taken at `cue_onset + response_time` ([#176](https://github.com/DuguidLab/mesoscopy/issues/176)).
+
 ## [0.13.2] - 2026-09-23
 
 ### Added